Question #013ce

1 Answer
Jan 27, 2018

As proved below

Explanation:

Assumed #(a2) / (b2)# as #a^2 / b^2#

Given : Sides are in the ratio #a / b#

Let a1, a2, a3 be the sides of triangle a & b1, b2, b3 be the sides of triangle b

Since the two triangles are similar, corresponding angles of the two triangles are equal.

Area of a triangle #A_T = (1/2) a * h = (1/2) a b sin C#

Since /_C is equal in both the triangles,

#A_a / A_b =( cancel(1/2)a1* a2 cancelsin (A3)) / (cancel(1/2) b1* b2cancelsin(B3)) = (a1 * a2 ) / (b1 * b2)#, as #sin (A3) = sin (B3)#

#A_a / A_b = ((a1)/(b1)) * ((a2) / (b2))#

We know #(a1) / (b1) = (a2) / (b2) = a/b#

Hence #A_a / A_b = (a/b) * (a/b) = a^2 / b^2#