(Q6) Prove that the ratio of areas of two similar triangles is equal to the square of the ratio of their corresponding medians.

ABCDXYZW

Solution :

Given : ∆ABC ∼ ∆XYZ

R.T.P :
∆ABC
∆XYZ
=
AD2
XW2

Proof :We know that the ratio of areas of two similar triangles is equal to the ratio of the squares of their corresponding sides.

∆XYZ
=
AB2
.....(1) [∵ ∆ABC ∼ ∆XYZ]

In ∆ABD and ∆XYW

∠B = ∠

∠D = ∠ = °

From AA similarity,

∼ ∆

∆ABD
∆XYW
=
=
.....(2)

From (1) and (2),

=

Hence the ratio of areas of two similar triangles is to the squares of ratio of their corresponding medians.