Topic C: Congruence and angle relationships

Topic C includes lessons 11-14 and covers definition of congruence and some basic properties, angles associated with parallel lines, angle sum of a triangle, and more on the angles of a triangle.

Congruence and similarity — Basic example

Congruence and similarity — Harder example

Angles, parallel lines, & transversals

Parallel & perpendicular lines

Missing angles with a transversal

Angle relationships with parallel lines

Measures of angles formed by a transversal

Equation practice with angles

Angles in a triangle sum to 180° proof

Triangle exterior angle example

Find angles in triangles

Find angles in isosceles triangles

Worked example: Triangle angles (intersecting lines)

Worked example: Triangle angles (diagram)

Finding angle measures between intersecting lines

Finding angle measures using triangles

Triangle angle challenge problem

Triangle angle challenge problem 2