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, 2015

Geometry Difficulty 1.5 Junior Find the answer Canada

In the rectangle shown, the area of the shaded region is

Pick one

Solution

The rectangle has area $5\times12=60$ cm $^2$ .

Each of the two congruent unshaded triangles has area $\frac12\times2\times5=5$ cm $^2$ .
The area of the shaded region is equal to the area of the rectangle minus the areas of the two unshaded triangles, which is $60-5-5=50$ cm $^2$ .

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