Question

PQR is an isosceles triangle with PQ = QR. If mQPR = 40°, what is mPQR?

30°

40°

60°

80°

100°

Answer 1

For an isosoceles triangle, if two sides are the same length, then the two nonincluded angles are the same measure. A generic picture of that would be:



As in the two sides marked x are the same length and the angles marked \(\alpha\) are the same measure. Since that is true, see if you can piece together the measure of the angle you need :)