A conjecture and the two-column proof used to prove the conjecture are shown. Given: the measure of angle C B D equals 90 degrees. Prove: triangle A B C is a right triangle. Ray B D extends down and perpendicular from point B on segment B C. Drag an expression or phrase to each box to complete the proof. Statement Reason 1. m∠CBD=90° Given 2. ∠ABC and ∠CBD are supplementary. Response area 3. Response area Definition of supplementary 4. m∠ABC+90°=180° Response area 5. Response area Subtraction Property of Equality 6. ∠ABC is a right angle. Definition of right angle 7. △ABC is a right triangle. Definition of right triangle The option "Linear Pair Postulate" (3 of 4) has been grabbed. Press tab to choose where to drop it. Drop it by pressing the spacebar key. Cancel the operation by pressing escape.