Explanation:
Pythagoras Theorem
Here, we need to find the Hypotenuse, the longer side which is the one mirrored of the right angle, which here is labeled as 'm'
The formula to finding the longer side is
a²+b²=c²
It doesn't matter where a or b is, what's important is c always the longer side.
6²+4.5²=c²
36+20.25=c²
56.25=c²
c=
c=7.5
Another formula for finding the shorter side, just change the + into -