Question

Find the distance d from across the river. Assume the triangles are similar and the ratio of d to 90 feet is the same as the ratio of 90 ft to 30 feet.

Answer 1

Since the triangles are similar, we will use the idea of proportion to find the

distance d across the river.

That is;

$\frac{d}{90}=\frac{90}{30}$

cross-multiply

30d =8100

Divide both-sie of the equation by 30

d =270ft