A scalene triangle has 3 sides of different lengths and 3 unequal angles. An isosceles triangle has 2 sides of equal length. The dashes on the lines show they are equal in length. The angles at ...

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 ...