Rotating Right Angle Tool

Practice angle relationships, supplementary angles, straight angles, and solving angle equations with these related worksheets.

These lessons strengthen understanding of complementary, supplementary, vertical, and parallel line angle relationships.

Drag the movable point to rotate the angle model and observe how the angle measures change.

Use the visual model to connect angle relationships to equations involving unknown angle measures.

Hide or reveal information as needed so students can reason about the missing angle before checking their thinking.

Angles that form a straight angle add up to 180°.

Adjacent angles share a vertex and a side, but they do not overlap.

When an angle relationship stays the same, you can write and solve an equation to find an unknown angle measure.

Angle: A figure formed by two rays that share the same endpoint.

Ray: A part of a line that has one endpoint and continues forever in one direction.

Line: A straight path that continues forever in both directions.

Vertex: The common endpoint where the rays of an angle meet.

Angle Measure: The size of an angle, usually measured in degrees.

Degree: A unit used to measure angles.

Right Angle: An angle that measures exactly 90°.

Straight Angle: An angle that measures exactly 180°.

Adjacent Angles: Angles that share a vertex and a side but do not overlap.

Supplementary Angles: Two angles whose measures add up to 180°.

Complementary Angles: Two angles whose measures add up to 90°.

Angle Equation: An equation that uses angle relationships to find an unknown angle measure.

Supplementary angles have measures that add up to 180°.

\(m\angle A+m\angle B=180^\circ\)

Complementary angles have measures that add up to 90°.

\(m\angle A+m\angle B=90^\circ\)

Angle equations can be solved by using the total angle measure and the relationship between the parts.

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