24.39 is 9% of what number

You are assembling pieces of an iron gate to complete a fence. the finished gate will look like the one below. in order to assemble the gate it is important to under how the pieces are related. part 1: how are pies 1 and 2 in the archway related? part 2: how are the rectangular sections 5 and 6 in the center of the gate related to each other?

What is the size of the matrix resulting from

Which expression demonstrates the use of the commutative property of addition in the first step of simplifying the expression (-1+i)+(21+5i)+0