How do i algebraically solve this? (solve for x)

This figure consists of a rectangle and semicircle. what is the perimeter of this figure use 3.14 for pi 60.84m 72.84m 79.68m 98.52m

Can someone factor this fully? my friend and i have two different answers and i would like to know if either of them is right. you in advance. a^2 - b^2 + 25 + 10a

What is the point of inflection for the function f(x)=2cos4x on the interval (0, pi/2)