If the legs of an isosceles right triangle have a length of [tex]$15 \sqrt{2} \, \text{ft}$[/tex], what is the length of the hypotenuse?

A. 7.5 feet
B. [tex]$15 \sqrt{2}$[/tex] feet
C. [tex][tex]$15 \sqrt{3}$[/tex][/tex] feet
D. 30 feet



Answer :

In an isosceles right triangle, the lengths of the two legs are equal, and the relationship between the legs and the hypotenuse can be derived from applying the Pythagorean theorem.

Given:
- Each leg of the isosceles right triangle has a length of [tex]\( 15 \sqrt{2} \)[/tex] feet.
- Let [tex]\( L \)[/tex] denote the length of each leg.

Since it's an isosceles right triangle, we can use the Pythagorean theorem to find the length of the hypotenuse [tex]\( H \)[/tex]:

[tex]\[ H = \sqrt{L^2 + L^2} \][/tex]

First, substitute [tex]\( L = 15 \sqrt{2} \)[/tex]:

[tex]\[ H = \sqrt{(15 \sqrt{2})^2 + (15 \sqrt{2})^2} \][/tex]

Calculate the square of [tex]\( 15 \sqrt{2} \)[/tex]:

[tex]\[ (15 \sqrt{2})^2 = 15^2 \cdot (\sqrt{2})^2 = 225 \cdot 2 = 450 \][/tex]

Now, sum the squares of the legs (since they are equal and there are two of them):

[tex]\[ H = \sqrt{450 + 450} = \sqrt{900} \][/tex]

Simplify the square root:

[tex]\[ H = \sqrt{900} = 30 \][/tex]

Therefore, the length of the hypotenuse is:

[tex]\[ \boxed{30 \text{ feet}} \][/tex]