An isosceles triangle will have two angles the same size. In an equilateral triangle, all angles will be 60°. A right-angled triangle will have one angle that is 90°, which means the other two ...

To find the size of one interior angle of a regular polygon, divide the sum of the interior angles by the number of sides.

In the “classical” adventitious angle problem, for a given set of three angles a, b, and c measured in integral degrees in an isosceles triangle, a fourth angle θ (the derived angle), also measured in ...