4. Polygons and Angles
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In a polygon, the sum of the measures of the exterior angles — one at each vertex — is 360∘.
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We are given the following diagram.
We are asked to find the value of x. Notice that the x∘ angle is one of the exterior angles of the polygon in the diagram. To find the measure of the x∘ angle, we will first recall an important piece of information.
Exterior Angles of a Polygon |
In a polygon, the sum of the measures of the exterior angles — one at each vertex — is 360∘. |
This means that the sum of the exterior angles of the given triangle is also 360∘. Let's mark an exterior angle at each vertex of this triangle.