Answer:
the missing side of the triangle is of length 15
Step-by-step explanation:
This problem is asking to find the hypotenuse (longest side) of a right angle triangle, so we can use the Pythagorean theorem, which tells us that the square of the hypotenuse in a right angle triangle equals the addition of the squares of the legs of the triangle (in our case 9 and 12).
We can then find the length of the hypotenuse applying the square root on both sides:
[tex]hyp^2=leg_1^2+leg_2^2\\hyp^2=9^2+12^2\\hyp^2=81+144\\hyp^2=225\\hyp=\sqrt{225} \\hyp=15[/tex]
