Theorem Toolkit

Create an 8-slide classroom presentation for 7th-grade students on circle theorems. Include clear labeled diagrams and concise worked examples. Slide 1: vocabulary—radius, diameter, chord, circumference, arc, tangent, segment, sector, semicircle, and pi. Slide 2: angle at the center is twice the angle at the circumference on the same arc, with examples 120° → 60° and 35° → 70°. Slide 3: angles in the same segment subtended by the same chord are equal. Slide 4: an angle subtended by a diameter is 90°. Slide 5: opposite angles of a cyclic quadrilateral sum to 180°, plus an exterior angle equal to the interior opposite angle. Slide 6: tangent perpendicular to radius at contact, and two tangent lengths from the same external point are equal. Slide 7: tangent-chord alternate-segment theorem and the center-to-chord-midpoint perpendicular theorem. Slide 8: a repeatable routine—identify the structure, state the theorem, substitute, calculate, and write the reason—with one mixed worked example. Keep each slide visually uncluttered, include theorem names and angle markings, and do not include student response spaces or worksheet tasks. This is one 15-minute presentation, so use no more than one worked example per theorem family.

Lara from Teachy