Question

Use the given paragraph proof to write a two-column proof.
Given: Triangle XYZ is a right triangle.
ÐZ is a right angle.
Prove: ÐX and ÐY are complementary angles.
Triangle XYZ is a right triangle, and ÐZ is a right angle.
So, mÐZ = 90° by the definition of a right angle.
By the Triangle Sum Theorem, mÐX + mÐY + mÐZ = 180°.
By the Subtraction Property of Equality, mÐX + mÐY + mÐZ – mÐZ = 180° – mÐZ.
So, mÐX + mÐY = 90°. Therefore, ÐX and ÐY are complementary angles
by the definition of complementary angles.