Question

The sum of the interior angles of an n-gon is 3420°. How many sides does the n-gon have?

Answer 1

In order to solve we remember that the sum of internal angles of a polygon is given by:

$\text{anlge}=(n-2)\cdot180$

Where "n" is the number of sides.

So, we solve now:

$3420=(n-2)\cdot180\Rightarrow n-2=19$$\Rightarrow n=21$

So, the polygon has 21 sides.