Content Area: Mathematics ● Subject: High School: Geometry ● Category: Congruence

Skill: G.CO.1. Know precise definitions of angle, circle, perpendicular line, parallel line, and line segment, based on the undefined notions of point, line, distance along a line, and distance around a circular arc.

Content Area: Mathematics ● Subject: High School: Geometry ● Category: Circles

Skill: G-C.5. Derive using similarity the fact that the length of the arc intercepted by an angle is proportional to the radius, and define the radian measure of the angle as the constant of proportionality; derive the formula for the area of a sector.