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Problem 378

Geometry Difficulty 2.5 Find the answer CEMC Pascal · Canada · 2020

In the diagram, the large square has area 49, the medium square has area 25, and the small square has area 9. The region inside the small square is shaded. The region between the large and medium squares is shaded.

What is the total area of the shaded regions?

3333
5858
4545
2525
1313

A number or a short expression. Fractions can be typed as 3/2, and spacing doesn't matter.

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Official solution

The total area of the shaded region equals the area of the small square (9) plus the area between the large square and medium square.

Since the area of the large square is 49 and the area of the medium square is 25, then the area of the region between these squares is 4925=2449 - 25 = 24.

Therefore, the total area of the shaded region is 9+24=339+24=33.

Source: CEMC, University of Waterloo, licensed CC-BY-NC-4.0. Statement reproduced verbatim; metadata (topic, difficulty, ordering) added by this project.