Question

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

x + z = y
y + z = x
x + y + z = 180 degrees
x + y + z = 90 degrees

Answer 1

y + z = x

Explanation:

The external angle of a triangle is equal to the sum of the 2 opposite interior angles.

x is an exterior angle of the triangle, thus

y + z = x