### Home > GC > Chapter 6 > Lesson 6.2.3 > Problem 6-62

6-62.

The angle that is 18*x* - 10° and the angle 7*x* are complementary.

Complementary means the angles add up to _____

Adjacent angle pairs that form a straight line are supplementary and base angles of an isosceles triangle are equal.

*x* = 55°

First solve for *y*, then solve for *x*.

3*y* − 12° + 63° = 180°

Since the triangle is isosceles, start by solving for *x*.

Next, solve for the unknown interior angle.

Then use the Law of Sines to solve for *y*.

Refer to the Math Notes box in Lesson 5.3.2 if you need help remembering the Law of Sines.