so since this is a right triangle you can use the Pythagorean Theorem to find the missing side. the two sides you know are 'a' and 'b' and the missing side is 'c'. the theorem says that:
a^2+b^2=c^2
so:
9^2 +40^2=c^2
solve for the exponents:
81 +1600=c^2
1681=c^2
and now, since 1681 is the missing side's length squared, we must find the square root of 1681, which is 41
And I’m just here to add onto what LoveHannahXO said earlier. You might not need this, but just in case, that “^2” thingy was the square because you can’t do a small 2 on mobile
