Question

Prove that the diagonals of a rectangle bisect each other.
The midpoint of AC is

Answer 1

(a,b)

Explanation:

we know that midpoint of each diagonal is (a,b),

is easy to check that

AC has equation
`bx-ay=0`

and BD has equation
`bx+ay=2ab`

which have intersection (common) point on (a,b).