to show that the diagonals of rectangle are equal to each other
Answers
Step-by-step explanation:
The opposite sides of rectangles are equal. The diagonals of rectangles bisect each other. Any two adjacent angles are supplementary (obviously, since they all measure 90°) The opposite angles are equal (again, obviously, since all interior angles measure 90°)
The opposite sides of rectangles are equal. The diagonals of rectangles bisect each other. Any two adjacent angles are supplementary (obviously, since they all measure 90°) The opposite angles are equal (again, obviously, since all interior angles measure 90.
Theorem
The diagonals of a rectangle are equal.
Proof
Let ABCD be a rectangle.
We prove that AC = BD.
In the triangles ABC and DCB:
BC = CB (common)
AB = DC (opposite sides of a parallelogram)
angleABC =angleDCA = 90° (given)
so triangleABC ≡ triangleDCB (SAS)
Hence AC = DB (matching sides of congruent triangles).
This means that AM = BM = CM = DM, where M is the
intersection of the diagonals. Thus we can draw a single
circle with centre M through all four vertices. We can
describe this situation by saying that, ‘The vertices of
a rectangle are concyclic’.