Circle A and B are concircle roundgruent. AB equals 18 and CD equals 12. What is the radius of the circle. Round to the nearest 10th place.
Accepted Solution
A:
Answer:Step-by-step explanation:A small secret: AC is the radius. It is also the hypotenuse of a right triangle. The two lines you have drawn in are perpendicular.So 1/2 CD is one leg of the right triangleAnd 1/2 AB is the other leg of the right triangle1/2 CD= 1/2 *12 = 61/2 AB = 1/2 * 18 = 9Let 1/2 CD = aLet 1/2 AB = bLet the radius = cc^2 = 6^2 + 9^2 c^2 = 36 + 81c^2 = 117 Take the square root of both sides.sqrt(c^2) = sqrt(117)c = sqrt(3 * 3 * 13) The rule is to take out 1 of a pair of equal roots and throw the other away.c = 3 * sqrt(13)Since the radius = c, the answer is 10.82To the nearest tenth, the answer is 10.8