Pythagorean theorem = a^2 + b^2 = c^2
c^2 should be the longest side in the triangle (the hypotenuse)
so AB is 9 meters and it is the longest side so that side is c
since we have the longest side we have to change the formula to match the question so instead of a^2 + b^2 = c^2 its changed to c^2 - b^2 = a^2
c^2 - b^2 = a^2
9^2 - 7^2 = a^2
(9x9) - (7x7) = a^2
81 - 49 = a^2
32 = a^2
32 is equal to a) squared but since it is squared we need to change it to just "a"
so we take 32 and square root it
the square root of 32 is
5.656854249
rounding to the nearest tenth of a meter is
AC = 5.7m