The best videos, books, apps, and other learning resources our members recommend:
This video defines angles, shows several examples of angles, and teaches some simple rules for analyzing them using the degrees of a circle, a straight line, and perpendicular lines.
Do the angles in a triangle always add up to the same thing? Would I ask it if they didn’t? What do we know about the angles of a triangle if two of the sides are congruent (an isosceles triangle)...