Answer
$a=6\sqrt2$
Work Step by Step
Plugging in values into the Pythagorean Theorem gives:
$a^2 +7^2 = 11^2$
Simplfy by subtracting $7^2$ from both sides, we find:
$a^2 = 11^2-7^2 = 121-49 = 72$
To solve $a^2=72$, take the square root of both sides:
$\sqrt a^2 = \sqrt 72 = 36\times 2$
Simplifying gives the answer:
$a = 6\sqrt 2$
