Question

The sum of the measures of the interior angles in a convex polygon is 1,260°. How many sides does the polygon have?

Answer 1

The formula for working out the total interior is:

180(n-2) = 1260

So let’s rearrange by dividing both sides by 180 and find what n is:

n-2 = 7

Then let’s add 2 to both sides to find what n is:

n=9

Each interior angle is 1260/9 = 140°.
The sum of the interior angle and its corresponding exterior angle is 180°.

Therefore, the polygon has 9 sides. :)