Diagonals of a Rectangle Proof

Given: FGHI is a rectangle

Prove: The diagonals of a rectangle have equal lengths

*Using paragraph proof, until I learn how to format 2 columns*

We know that quadrialateral FGHI is a rectangle because it was given.

We can say that segments FI & GH are congruent using the definition of a rectangle. We can also say that angles I and H are rt angles by the definition of a rectangle. Because of the Right Angle Congruence Theorem, we know that angles I and H are congruent (that Thm. means all right angles are congruent to one another). Segments HI & IH are congruent by the Reflexive Prop. of congruence. So we know that Triangles FIH & GHI are congruent using the SAS postulate. Finally, we can say that segments FH & GI are congruent by CPCTC.