Given Rectangle ABCD with diagonals AC and BD Prove AC BD Move options to the blanks to complete the proof B A Because ABCD is a rectangle it is also a parallelogram Opposite sides of a parallelogram are congruent therefore AB By the reflexive property AD All interior angles of a rectangle are congruent therefore BAD ZCDA By the Side Angle Side Theorem A BAD Because corresponding parts of congruent triangles are congruent AC BD C D