The tangents to the circle that are parallel to the line Animation Play

The three circles Whiteboard exercise Play

The triangle Student activity Play

The triangle inscribed in a circle Whiteboard exercise Play

The yellow region Whiteboard exercise Play

Theorem – assumptions and claim Student activity Play

Theorem – assumptions and claim Whiteboard exercise Play

Three circles Student activity Play

Three circles – finding the arcs Whiteboard exercise Play

Three circles – finding the area Whiteboard exercise Play

Three fourths of a circle Animation Play

Three tears Animation Play

Torus Animation Play

Transforming the equation of the circle Whiteboard exercise Play

Transforming the equation of the circle Whiteboard exercise Play

Triangle and circle Animation Play

Trigonometric functions of the general angle Simulation Play

Trigonometric functions of the general angle Student activity Play

Trisecting an angle Animation Play

Two circles Whiteboard exercise Play

Two circles Student activity Play

Two circles Simulation Play

Two circles Student activity Play

Two circles Simulation Play

Two circles and a line Student activity Play