Maths-
General
Easy

Question

The centroid of the triangle ABC is (2, 3) and A = (4, 2), B = (4, 5) then the area of the
triangle ABC

  1. 6    
  2. 9    
  3. 8    
  4. 5    

hintHint:

We are given the coordinates of centroid of a ∆ABC. Centroid of a triangle is where three medians of a triangle intersect. We are given the values of two vertices of the triangle. We are asked to find the area. Using the centroid, we can find the third vertex of triangle. We will use the vertices to find the area.

The correct answer is: 9


    Let the centroid of the ∆ABC be denoted by G.
    The coordinates of the given points are as follows:
    A = (4, 2) = (x1,y1)
    B = (4, 5) = (x1,y2)
    C = (x3,y3)
    G = (2, 3) = (x,y)
    The relation between the centroid and vertices is given by the formula
    (x,y) = open parentheses fraction numerator x subscript 1 plus space x subscript 2 space plus space x subscript 3 over denominator 3 end fraction comma fraction numerator y subscript 1 space plus space y subscript 2 plus space y subscript 3 over denominator 3 end fraction close parentheses
    So we can write,
    x space equals fraction numerator x subscript 1 space plus space x subscript 2 space plus space x subscript 3 over denominator 3 end fraction
space 2 equals fraction numerator 4 space plus space 4 space plus space x subscript 3 over denominator 3 end fraction
6 space minus space 4 space minus space 4 space equals space x subscript 3
x subscript 3 space equals space end subscript minus 2
    y space equals fraction numerator y subscript 1 space end subscript plus space y subscript 2 space plus space y subscript 3 over denominator 3 end fraction
3 space equals fraction numerator 2 space plus space 5 space plus space y subscript 3 over denominator 3 end fraction
9 space minus space 2 space minus space 5 space equals space y subscript 3
y subscript 3 space end subscript equals space 2
    The coordinates of C are (-2,2)
    Now, we will find the area.
    The formula for area using the vertices of a triangle is as follows:
    Area = equals 1 half open square brackets x subscript 1 left parenthesis y subscript 2 space minus space y subscript 3 right parenthesis space plus space x subscript 2 left parenthesis y subscript 3 space minus space y subscript 1 right parenthesis space plus space x subscript 3 left parenthesis y subscript 1 space end subscript minus y subscript 2 right parenthesis close square brackets
equals 1 half left square bracket 4 left parenthesis 5 space minus space 2 right parenthesis space plus space 4 left parenthesis 2 space minus space 2 right parenthesis space plus space left parenthesis negative 2 right parenthesis left parenthesis 2 space minus space 5 right parenthesis right square bracket
equals 1 half left square bracket 12 space plus space 0 space plus space 6 right square bracket
equals space 1 half cross times space 18
equals space 9 space
    The area of the triangle is 9 units

    For such questions, we should know the relation between centroid and vertices of a triangle. We should also know the formula of area using vertices of at triangle.

    Related Questions to study

    General
    Maths-

    The points (6, 8), (–2, 2) and (–6, –1) form

    The points (6, 8), (–2, 2) and (–6, –1) form

    Maths-General
    General
    Maths-

    25 men were employed to do a piece of work which they could finish in 20 days, but the men drop off by 5 at the end of every 10 days. In what time will the work be completed?

    25 men were employed to do a piece of work which they could finish in 20 days, but the men drop off by 5 at the end of every 10 days. In what time will the work be completed?

    Maths-General
    General
    Maths-

    A can complete a piece of work in 15 days. B can complete it in 10 days. With the help of C, they can complete the work in 4 days. They all worked together and earned a total of Rs. 750. Find C’s share

    L.C.M is the least common multiple. We should know the concepts of work and wages.

    A can complete a piece of work in 15 days. B can complete it in 10 days. With the help of C, they can complete the work in 4 days. They all worked together and earned a total of Rs. 750. Find C’s share

    Maths-General

    L.C.M is the least common multiple. We should know the concepts of work and wages.

    parallel
    General
    Maths-

    Three persons A, B and C finished a piece of work. A worked at it for 5 days, B for 7 days and C for 9 days. Their daily wages are in the ratio of 4 : 3 : 2 and the total earning amounted to Rs. 118. What was the daily wage of A?

    Three persons A, B and C finished a piece of work. A worked at it for 5 days, B for 7 days and C for 9 days. Their daily wages are in the ratio of 4 : 3 : 2 and the total earning amounted to Rs. 118. What was the daily wage of A?

    Maths-General
    General
    Maths-

    A and B can do a piece of work in 40 days while B and C can do it in 60 days. If A is twice as good a workman as C, then C alone will do the work in

    For such questions, we should know the concept of work and efficiency.

    A and B can do a piece of work in 40 days while B and C can do it in 60 days. If A is twice as good a workman as C, then C alone will do the work in

    Maths-General

    For such questions, we should know the concept of work and efficiency.

    General
    Maths-

    Meena, Neena and Raveena can knit a shawl in 6, 4 and 8 hours respectively. What portion of the shawl will they knit in 1 hour if they work together?

    L.C.M is the smallest common multiple of the given numbers.

    Meena, Neena and Raveena can knit a shawl in 6, 4 and 8 hours respectively. What portion of the shawl will they knit in 1 hour if they work together?

    Maths-General

    L.C.M is the smallest common multiple of the given numbers.

    parallel
    General
    Maths-

    Tap A can fill a tank in 8 hours and tap B can empty the tank in 12 hours. How long would it take to fill the empty tank if both of them are opened together?

    For such questions, we should see if the taps are filling or emptying the tank. We should also be careful about subtraction or addition of fractions. We should make the denominator equal or take L.C.M before subtracting or adding.

    Tap A can fill a tank in 8 hours and tap B can empty the tank in 12 hours. How long would it take to fill the empty tank if both of them are opened together?

    Maths-General

    For such questions, we should see if the taps are filling or emptying the tank. We should also be careful about subtraction or addition of fractions. We should make the denominator equal or take L.C.M before subtracting or adding.

    General
    Maths-

    Latha, Chetan and Amar started a business. Latha invests Rs 5000 for 2 years, Chetan invests Rs.1000 for 15 months and Amar invests Rs 3000 for 10 months. If there is a profit of Rs. 1925, find out the share of Latha

    Latha, Chetan and Amar started a business. Latha invests Rs 5000 for 2 years, Chetan invests Rs.1000 for 15 months and Amar invests Rs 3000 for 10 months. If there is a profit of Rs. 1925, find out the share of Latha

    Maths-General
    General
    Maths-

    The population of a town was 1,60,000 two years ago. If it has increased by 3% and 5% respectively in the last two years, find its present population

    For such questions, we should be careful while finding the percentage increase in the population. We have to add the increased in number of population to the original population to get new population. We have to careful about order of increase in population.

    The population of a town was 1,60,000 two years ago. If it has increased by 3% and 5% respectively in the last two years, find its present population

    Maths-General

    For such questions, we should be careful while finding the percentage increase in the population. We have to add the increased in number of population to the original population to get new population. We have to careful about order of increase in population.

    parallel
    General
    Maths-

    The difference between C.I and S.I for 2 years at 10% per annum is Rs 50. Find the sum

    For such questions, we should know the formulas for simple and compound interest.

    The difference between C.I and S.I for 2 years at 10% per annum is Rs 50. Find the sum

    Maths-General

    For such questions, we should know the formulas for simple and compound interest.

    General
    Physics-

    An electric wire of length ‘I’ and area of cross-section a has a resistance R ohms. Another wire of the same material having same length and area of cross-section 4a has a resistance of

    An electric wire of length ‘I’ and area of cross-section a has a resistance R ohms. Another wire of the same material having same length and area of cross-section 4a has a resistance of

    Physics-General
    General
    Physics-

    The resistance of a wire of uniform diameter d and length L is R. The resistance of another wire of the same material but diameter 2d and length 4L will be

    The resistance of a wire of uniform diameter d and length L is R. The resistance of another wire of the same material but diameter 2d and length 4L will be

    Physics-General
    parallel
    General
    Maths-

    Reena borrowed Rs 8000 from Neena for 2 years at 12 fraction numerator 1 over denominator 2 end fraction percent sign per annum compound interest. What C.I. did Veena pay to Neena?

    Compound interest is the internet based on the principal amount and also the interest added to the sum. It's interst on that total amount.

    Reena borrowed Rs 8000 from Neena for 2 years at 12 fraction numerator 1 over denominator 2 end fraction percent sign per annum compound interest. What C.I. did Veena pay to Neena?

    Maths-General

    Compound interest is the internet based on the principal amount and also the interest added to the sum. It's interst on that total amount.

    General
    General

    A 500 gm packet of tea is sold for Rs 80 and a tooth brush costing Rs 11 is given free with it. The shopkeeper thus makes a profit of 15% on it. What did the shopkeeper pay for it?

    In such questions, we should be careful about finding the actual selling price before finding the cost price. We should know the formula to find the profit.

    A 500 gm packet of tea is sold for Rs 80 and a tooth brush costing Rs 11 is given free with it. The shopkeeper thus makes a profit of 15% on it. What did the shopkeeper pay for it?

    GeneralGeneral

    In such questions, we should be careful about finding the actual selling price before finding the cost price. We should know the formula to find the profit.

    General
    Maths-

    The place with which a 7-digit number starts in Indo-Arabic System is

    For such questions we should know the places of digits in Indo-Arabian system. The key part is counting the zeros.

    The place with which a 7-digit number starts in Indo-Arabic System is

    Maths-General

    For such questions we should know the places of digits in Indo-Arabian system. The key part is counting the zeros.

    parallel

    card img

    With Turito Academy.

    card img

    With Turito Foundation.

    card img

    Get an Expert Advice From Turito.

    Turito Academy

    card img

    With Turito Academy.

    Test Prep

    card img

    With Turito Foundation.