Math CentralQuandaries & Queries


Question from Shriya, a student:

All the angles of a polygon are either 155° or 140°
There are twice as many angles of 155 °or 140°.
Find the number of sides of the polygon


I can help get you started.

Look at one of the vertices $V$ where the internal angle measures $140^{0}.$ The external angle then measures $180^0 - 140^0 = 40^{0}.$

polygon vertex

What is the measure of the external angle at a vertex where the internal angle measures $155^{0}?$

Now look at Walter's note about the sum of the measures of the external angles of a convex polygon.

Write back if you need more assistance,

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