Question 5
Three semicircles are drawn as in the diagram below. Let AB be a segment which is drawn from the diameter to the circumference of the largest semicircle and tangent to two shaded semicircles. What is the area, in cm², of the largest semicircle that is not covered by the smaller semicircles if the length of AB is 28 cm? (Use $\pi=\frac{22}{7}$)
