Browse · MATH
Printjmc
geometry senior
Problem
A circle of radius 1 is tangent to a circle of radius 2. The sides of are tangent to the circles as shown, and the sides and are congruent. What is the area of ?

Solution
Let and denote the centers of the smaller and larger circles, respectively. Let and be the points on that are also on the smaller and larger circles, respectively. Since and are similar right triangles, we have As a consequence,
Let be the midpoint of . Since and are similar right triangles, we have So the area of is
Let be the midpoint of . Since and are similar right triangles, we have So the area of is
Final answer
16\sqrt{2}