# Nonagon

Calculate the area and perimeter of a regular nonagon if its radius of the inscribed circle is r = 10cm

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**Matematik**

try to start with angle 360/9 = 40°... Draw nine isosceles triangles with base a=4 cm and opposite angle 40°.

Or if you may calculate diameter of described circle - draw a circle and divide it into nine equal segments. (divide by 40° angle)

Or if you may calculate diameter of described circle - draw a circle and divide it into nine equal segments. (divide by 40° angle)

Tips to related online calculators

Pythagorean theorem is the base for the right triangle calculator.

See also our trigonometric triangle calculator.

See also our trigonometric triangle calculator.