1) Two circles intersect at A and B. A common external tangent is tangent to the circles at T and U as shown. Let M be the intersection of line AB and TU. If AB = 9 and BM = 3 find TU.
Picture: https://latex.artofproblemsolving.com/c/5/0/c50a548001dc09c6eb63031398f6a77787276a50.png
2) If AB = 3, AC = 8 and BS = 21, find the area of the circle.
Picture: https://latex.artofproblemsolving.com/7/a/5/7a599f15c79349567f1b440d1e75d9
