Gmat_mission wrote: ↑

Sun Apr 11, 2021 2:53 am

The perimeter of a certain isosceles right triangle is \(16+16\sqrt2.\) What is the length of the hypotenuse of the triangle?

(A) \(8\)

(B) \(16\)

(C) \(4\sqrt2\)

(D) \(8\sqrt2\)

(E) \(16\sqrt2\)

Answer: B

Source: GMAT Prep

An IMPORTANT point to remember is that, in any isosceles right triangle, the sides have length x, x, and x√2 for some positive value of x.

Note: x√2 is the length of the hypotenuse, so our goal is to find the value of x√2

From here, we can see that the perimeter will be x + x + x√2

In the question, the perimeter is 16 + 16√2, so we can create the following equation:
x + x + x√2 = 16 + 16√2,
Simplify: 2x + x√2 = 16 + 16√2
IMPORTANT: Factor x√2 from the left side to get : x√2(√2 + 1) = 16 + 16√2
Now factor 16 from the right side to get: x√2(√2 + 1) = 16(1 + √2)
Divide both sides by (1 + √2) to get: x√2 = 16

Answer = B

Cheers,
Brent