CPM Homework Help : INT2 Problem 2-56

For each triangle below, solve for the variable and answer the questions.

Triangle, A,B,C, labeled as follows: Angle, B, x, angle, A, 2, x. Side, A B, 2 tick marks, side, A C, 2 tick marks. An isosceles triangle where the base line is extended to the right outside of the triangle. The left interior angle is 71 degrees and the exterior angle is labeled y.

Solve for $x$ . What kind of triangle is $∆ABC$ ? Be specific.
Hint (a):
What is true about the base angles of isosceles triangles?
Answer (a):
$x = 45°$
Solve for $y$ . What kind of triangle is shown in the figure? Be specific.
Hint (b):
Notice the supplementary angle with $y$ . A supplementary angle adds up to $180^\circ$ . Can you form an equation to solve for $y$ ?