1. Since b and 42° are across from each other, they are congruent angles. So, b would equal 42°. We still don't know the value of c, we can do 42 + 42 + 2c = 360, because again, the two angles are across from each other. The whole equation equals to 360 because the intersecting lines kind of forms a circle and a circle is 360°.
2. All the angles of a triangle add up to 180°. Since the triangle is a right triangle, we know 2 out of the 3 angles. The equation would then be, 62 + 90 + s = 180.
