If a triangle has a leg of 21 ft, and a hypotenuse of 35 ft, what is the measure of the other leg?

1 Answer
Mar 20, 2018

See a solution process below:

Explanation:

Note: Assumption is this is a right or 90^o triangle.

The Pythagorean Theorem states:

For a right triangle

a^2 + b^2 = c^2

Where:

a and b are legs of the right triangle and c is the hypotenuse.

Substituting for a and c and solving for b gives:

(21"ft")^2 + b^2 = (35"ft")^2

441"ft"^2 + b^2 = 1225"ft"^2

441"ft"^2 - color(red)(441"ft"^2) + b^2 = 1225"ft"^2 - color(red)(441"ft"^2)

0 + b^2 = 784"ft"^2

b^2 = 784"ft"^2

sqrt(b^2) = sqrt(784"ft"^2)

b = 28"ft"

The measure of the other leg is 28 feet