Question

What is the distance across the lake?

Answer 1

Given:

Height of right triangle = 9 mi

Hypotenuse = 17.5 mi

Base of right triangle = Distance across lake

To find:

The distance across the lake.

Solution:

Using Pythagoras theorem:

In right triangle, square of the hypotenuse is equal to the sum of the squares of the other two sides.

$\Rightarrow 9^2+base^2=(17.5)^2$

$\Rightarrow 81+base^2=306.25$

Subtract 81 from both sides.

$\Rightarrow 81+base^2-81=306.25-81$

$\Rightarrow base^2=225.25$

Taking square root on both sides.

⇒ base = 15

The distance across the lake 15 mi.