c=7√2 inches
In this question, we have an isosceles triangle, which is also the right one.
So we can find the measure of side c, using the Pythagorean Theorem. Note that c is the hypotenuse since it is the opposite side to the right angle.
c²=7²+7²
c² =49 +49
c² =98
√c²=√98
c=7√2 inches