Congruent tangents theorem

Students will learn the following theorem: If two tangent segments meet at a point, then those segments must be congruent. Start by having students draw a circle and an arbitrary point outside the circle. Then have them draw the two tangent segments connecting the point to the circle. Have them make a conjecture. Once students have made the correct conjecture, have them attempt to prove it. This theorem is easy to prove, it's pretty much a direct consequence of the hypotenuse-leg theorem. After students have given it a go, show them this proof.