Angle: The measure of the opening between two intersecting lines is called an angle. Unit: The unit of angle is radians or degrees. Angle formula: There are different types of formulas for calculating ...

Polygons can be regular or irregular. If the angles are all equal and all the sides are equal length it is a regular polygon. To find the sum of interior angles in a polygon divide the polygon into ...

The Mathematics Teacher (MT), an official journal of the National Council of Teachers of Mathematics, is devoted to improving mathematics instruction from grade 8-14 and supporting teacher education ...