Question

Can someone help?!

Which relationship is always true for the angles r, x, y, and z of triangle ABC?

A triangle is shown with a leg extending past the top vertex. The vertices are labeled ABC. Angle y is located inside the triangle at vertex B. Angle z is located inside the triangle at vertex C. Angle x is located outside the triangle between beside vertex A and the extended leg. Angle r is located inside the triangle at vertex A.
A. x + z = y
B. 180 degrees − x = r
C. x + y + z = 180 degrees
D. x + y + z = 90 degrees

Answer 1

May I help?

Answer 2

It would be nice!

Answer 3

That is with my pleasure!

Are you familiar with the exterior angle of a triangle?