Difference between revisions of "2012 AMC 10B Problems/Problem 2"
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A circle of radius 5 is inscribed in a rectangle as shown. The ratio of the length of the rectangle to its width is 2:1. What is the area of the rectangle? | A circle of radius 5 is inscribed in a rectangle as shown. The ratio of the length of the rectangle to its width is 2:1. What is the area of the rectangle? | ||
+ | |||
+ | <asy> | ||
+ | draw((0,0)--(0,10)--(20,10)--(20,0)--cycle); | ||
+ | draw(circle((10,5),5));</asy> | ||
<math> \textbf{(A)}\ 50\qquad\textbf{(B)}\ 100\qquad\textbf{(C)}\ 125\qquad\textbf{(D)}\ 150\qquad\textbf{(E)}\ 200 </math> | <math> \textbf{(A)}\ 50\qquad\textbf{(B)}\ 100\qquad\textbf{(C)}\ 125\qquad\textbf{(D)}\ 150\qquad\textbf{(E)}\ 200 </math> |
Revision as of 14:52, 23 August 2012
Problem
A circle of radius 5 is inscribed in a rectangle as shown. The ratio of the length of the rectangle to its width is 2:1. What is the area of the rectangle?
Solution
Note that the diameter of the circle is equal to the shorter side of the rectangle. Since the radius is , the diameter is . Since the sides of the rectangle are in a ratio, the longer side has length . Therefore the area is or .