What is the measure of the hypotenuse of an isosceles right triangle with leg lengths 6?

Given, the triangle is isosceles, so, two sides are equal in length.

Also, given the triangle is a right angled triangle, hence, the two equal sides of the triangle are the legs of the triangle excluding the hypotenuse.

Leg length = 6 

Hence, 

(Hypotenuse)² = (leg)² + (other leg)² = 6² + 6² = 36 + 36 = 72

Hypotenuse = √(72) = 8.48528137424 ≈ 8.49

The answer would be 7 cages