Question

If the base angles of a triangle are congruent, use the Law of Sines to show the triangle is isosceles.

Answer 1

The Isosceles Triangle Theorem States that if a triangle contains 2 congruent sides, then the angles opposite those sides are congruent. This theorem can be proved using the Law of Sines: The Law of Sines states that: asinA=bsinB=csinC If a=c, making △ABC an isosceles triangle, then asinA=asinC!