To solve the two problems below you need to know 1) The area of a circle is Πr2, with r as radius and that the area of a semicircle is of course half of the circle, ½Πr2 and 2) the angle in a semicircle theorem. Problem 1 Prove that the area of the solid green semicircle

The circumference of a circle is π x diameter so the length of a semicircle is (1/2)π x d. The solution to problem #2 is shown below. Let the diameters of the smaller circles be p, q, r, s. Use the formula to find the lengths of each semicircle. The same thinking is applicable to semicircle

If you figured out Semicircle road trip problem #1, you will find this second problem easy. The challenge is setting-up the solution/ explanation and not really in figuring out which road is longer. If you have an explanation, share them in the comment section. Problem There are two ways to get from Town A to