Question

which number completes the pythagorean triple of 9, 12, x?
a $\frac{5}{3}$
b 5
c 10
d 12
e 15

Explanation:

Step1: Recall Pythagorean theorem

For right triangle sides $a,b,c$ (hypotenuse $c$): $a^2 + b^2 = c^2$

Step2: Substitute given values

$9^2 + 12^2 = x^2$
$\Rightarrow 81 + 144 = x^2$

Step3: Calculate sum and solve for x

$225 = x^2$
$\Rightarrow x = \sqrt{225} = 15$

Answer:

E 15