Question

A right triangle has a leg of 3 feet and a hypotenuse of 4 feet. What is the length of the other leg? Enter your answer, as a decimal rounded to the nearest tenth, in the box.

Answer 1

Let $c$ be the hypotenuse of the triangle and $a,b$ be the length of the other two sides. Then using Pythagoras theorem,

$a^2+b^2=c^2\\ a^2=c^2-b^2\\\ a=\sqrt{c^2-b^2}$

Substitute numerical values, $c=4,b=3$. then,

$a=\sqrt{4^2-3^2}\\ a=\sqrt{7}\\ a=2.646$

The length of the other leg rounded to nearest 10th is $2.6$.

Answer 2

A² + b² = c²
~~~~~~~~
a² + 3² = 4²
a² + 9 = 16
a² = 7
a² = 2.6 ft