These overlapping squares each have sides of 10 cm. One corner of one square is at the center of the other square. What is the area of the shaded region?
Solution
In the figure, Region A = Region B (congruent triangles by ASA).
Therefore A + C = B + C and B + C = 25 sq cm.
Therefore A + C = 25 sq cm.
Observe what you see when you rotate one of the squares around the center vertex.
