A steal of a deal — get four angles for the value of one. An interactive resource allows individuals to visualize all four angles that have the same reference angle. Pupils answer questions by using the interactive to create the...

Examine vertical angles from a different angle. Moving one line in an intersecting pair of lines lets users see relationships between vertical angles. They finish by answering some machine-scored questions on the topic.

Geometric constructions build relationships —by simply manipulating simple tools. An interactive lesson presents a completed construction of a segment bisector and has learners analyze the important aspects. Ultimately, they should be...

Measure angles in more than one way. The interactive introduces the concept of measuring angles from 0 to 360 degrees. Scholars explore the relationships between the angle and reference angles along with coterminal angles.

Are there only three options: parallel, perpendicular, or intersecting? Scholars move a given line in an interactive to change its orientation with respect to another line. The interactive indicates whether the lines are parallel,...