Two-Column Proof
| Statement | Reason | |------------------------------------------------------|----------------------------------------------------------------------------------------| | 1. Define LMNO as a rectangle with vertices L, M, N, O. | By definition of a rectangle, opposite sides are equal and all angles are 90 degrees. | | 2. Draw diagonals LN and MO. | By definition, diagonals are segments connecting opposite vertices of a polygon. | | 3. Triangle LMO and triangle NMP are formed by the diagonals. | The diagonals intersect at point P. | | 4. LM = ON and LO = MN (opposite sides of rectangle). | Properties of rectangles (opposite sides are equal). | | 5. Angle LMO = angle NMP (both are vertical angles). | Vertical angles are always congruent. | | 6. Triangle LMO ≅ triangle NMP by the Side-Angle-Side (SAS) postulate. | Two sides and the angle between them are congruent in both triangles. | | 7. By the congruence of triangles LMO and NMP, it follows that the diagonals LN and MO are congruent. | Corresponding parts of congruent triangles are congruent (CPCTC). |
Conclusion
Therefore, the diagonals of rectangle LMNO, LN and MO, are congruent.