Interior Angles of a Polygon Calculator
⬛ Area & perimeter (2D). Use the Interior angles of a polygon formula to find sum of interior angles, number of sides: pick the value you want, type the others, and the answer updates as you go.
Sum of interior angles540 °
Pick the ○ next to the value you want to find, fill in the others, and it solves as you type.
What each letter means
| Quantity | Unit |
|---|---|
| Sum of interior angles | ° |
| Number of sides | no unit |
Worked example
Find the sum of interior angles when Number of sides = 5.
Using S = (n - 2) × 180°: Sum of interior angles = 540 °.
Frequently asked questions
What is the formula for Interior angles of a polygon?
S = (n - 2) × 180°.
What do the letters stand for, and what units are used?
Sum of interior angles in °, Number of sides.
How do you calculate sum of interior angles?
Put the values into S = (n - 2) × 180°. For example, with Number of sides = 5, sum of interior angles = 540 °.
Can I solve for a different value?
Yes. In the calculator above, pick the circle next to any value (sum of interior angles, number of sides) and fill in the others: it rearranges the formula for you.
