Maths-
General
Easy

Question

A B C text  is a right triangle with  end text straight angle A equals 90 to the power of ring operator BL text  and  end text CM text  are its medians. Prove that  end text 4 open parentheses BL squared plus CM squared close parentheses equals 5 BC squared text .  end text

The correct answer is: Hence proved


    Solution :-
    Aim  :- Prove that 4 open parentheses B L squared plus C M squared close parentheses equals 5 B C squared
    Hint :- Applying pythagoras theorem to both triangles ACM and BLA. find the BL2
    and CM2  add them and substitute proper conditions to prove the condition .
    Explanation(proof ) :-
    Given,   BL and CM are the medians of a triangle ABC
    M is midpoint of AB i.e AM = ½ AB
    L is mid point of AC i.e AL = ½ AC
    Applying pythagoras theorem to  triangle BLA we get ,
    B L squared equals A L squared plus A B squared
    As we know AL = ½ AC we getB L squared equals A B squared plus fraction numerator A C squared over denominator 4 end fraction minus Eq 1
    Applying pythagoras theorem to  triangle ACM we get ,
    C M squared equals A C squared plus A M squared
    As we know AM = ½ AB we get C M squared equals A C squared plus fraction numerator A B squared over denominator 4 end fraction minus Eq 2— Eq2
    Applying pythagoras theorem to  triangle ABC we get ,
    A B squared plus A C squared equals B C squared minus Eq 3


    Adding Eq1 and Eq2 we get ,
    B L squared plus C M squared equals A B squared plus fraction numerator A C squared over denominator 4 end fraction plus A C squared plus fraction numerator A B squared over denominator 4 end fraction
    not stretchy rightwards double arrow B L squared plus C M squared equals 5 over 4 open parentheses A B squared plus A C squared close parentheses
    Substitute Eq 3 in the above , we get 
    B L squared plus C M squared equals 5 over 4 open parentheses B C squared close parentheses not stretchy rightwards double arrow 4 open parentheses B L squared plus C M squared close parentheses equals 5 B C squared
    Hence proved

    Related Questions to study

    General
    Maths-

    Classify whether the following Surd is rational or irrational , justify 4√5+ 9

    Classify whether the following Surd is rational or irrational , justify 4√5+ 9

    Maths-General
    General
    Maths-

    PQR is a triangle in which PQ=PR.S is any point on the side PQ. Through S, a line is drawn parallel to QR intersecting PR at T. Prove that PS = PT.

    PQR is a triangle in which PQ=PR.S is any point on the side PQ. Through S, a line is drawn parallel to QR intersecting PR at T. Prove that PS = PT.

    Maths-General
    General
    Maths-

    text  In Triangle  end text A B C text , If  end text A D text  is the median show that,  end text A B squared plus A C squared equals 2 open parentheses A D squared plus B D squared close parentheses

    text  In Triangle  end text A B C text , If  end text A D text  is the median show that,  end text A B squared plus A C squared equals 2 open parentheses A D squared plus B D squared close parentheses

    Maths-General
    parallel
    General
    Maths-

    Classify whether the following Surd is rational or irrational , justify 8-√48

    Classify whether the following Surd is rational or irrational , justify 8-√48

    Maths-General
    General
    Maths-

    Classify whether the following Surd is rational or irrational , Justify.√47+√8

    Classify whether the following Surd is rational or irrational , Justify.√47+√8

    Maths-General
    General
    Maths-

    In the figure, sides QP and RQ of a  straight triangle P R R are produced to points S and T respectively.
    If straight angle SPR equals 135 to the power of ring operator andstraight angle POT equals 110 to the power of ring operator, findstraight angle PRQ.

    In the figure, sides QP and RQ of a  straight triangle P R R are produced to points S and T respectively.
    If straight angle SPR equals 135 to the power of ring operator andstraight angle POT equals 110 to the power of ring operator, findstraight angle PRQ.

    Maths-General
    parallel
    General
    Maths-

    Simplify √8 - √18 + √50

    Simplify √8 - √18 + √50

    Maths-General
    General
    Maths-

    text  In a Triangle  end text A B C comma less than B greater than 90 to the power of ring operator text  and  end text A D text  is drawn perpendicular to  end text B C text . Prove that  end text A C squared equals A B squared plus B C squared plus 2 B C. B D

    text  In a Triangle  end text A B C comma less than B greater than 90 to the power of ring operator text  and  end text A D text  is drawn perpendicular to  end text B C text . Prove that  end text A C squared equals A B squared plus B C squared plus 2 B C. B D

    Maths-General
    General
    Maths-

    Prove in the given figure, side QR of a straight triangle space PQR  is produced to a point S.
    If the bisector of  straight angle PQR and straight angle PRS  meet at the point T, then prove
    straight angle QTR equals 1 half straight angle QPR

    Prove in the given figure, side QR of a straight triangle space PQR  is produced to a point S.
    If the bisector of  straight angle PQR and straight angle PRS  meet at the point T, then prove
    straight angle QTR equals 1 half straight angle QPR

    Maths-General
    parallel
    General
    Maths-

    In an equilateral triangle ABC,D  is a point on the side BC , such that BD equals 1 third BC . Prove that
    9 AD squared equals 7 AB squared

    In an equilateral triangle ABC,D  is a point on the side BC , such that BD equals 1 third BC . Prove that
    9 AD squared equals 7 AB squared

    Maths-General
    General
    Maths-

    In the figure, find the value of x.

    In the figure, find the value of x.

    Maths-General
    General
    Maths-

    text  In a Triangle  end text A B C comma less than B less than 90 to the power of ring operator text  and  end text A D text  is drawn perpendicular to  end text B C text . Prove that  end text A C squared equals A B squared plus B C squared minus 2 B C. B D

    text  In a Triangle  end text A B C comma less than B less than 90 to the power of ring operator text  and  end text A D text  is drawn perpendicular to  end text B C text . Prove that  end text A C squared equals A B squared plus B C squared minus 2 B C. B D

    Maths-General
    parallel
    General
    Maths-

    Simplify √12 - √48 +√1323

    Simplify √12 - √48 +√1323

    Maths-General
    General
    Maths-

    In straight triangle A B C, the bisectors of straight angle A B C and straight angle B C A intersect each other at O. Prove that straight angle B O C equals 90 to the power of ring operator plus 1 half straight angle A

    In straight triangle A B C, the bisectors of straight angle A B C and straight angle B C A intersect each other at O. Prove that straight angle B O C equals 90 to the power of ring operator plus 1 half straight angle A

    Maths-General
    General
    Maths-

    and  are the medians of a straight triangle ABC right angled at . Prove that  4 open parentheses BL squared plus C straight C squared close parentheses equals 5 BC squared.

    and  are the medians of a straight triangle ABC right angled at . Prove that  4 open parentheses BL squared plus C straight C squared close parentheses equals 5 BC squared.

    Maths-General
    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.