The coordinates for a rhombus are given as (2a, 0) (0, 2b), (-2a, 0), and (0.-2b). How do you write a plan to prove that the midpoints of the sides of a rhombus determine a rectangle using coordinate geometry?

1 Answer
Jan 12, 2017

Please see below.

Explanation:

Let the points of rhombus be A(2a, 0), B(0, 2b), C(-2a, 0) and D(0.-2b).

Let midpoints of AB be P and its coordinates are ((2a+0)/2,(0+2b)/2) i.e. (a,b). Similarly midpoint of BC is Q(-a,b); midpoint of CD is R(-a,-b) and midpoint of DA is S(a,-b).

It is apparent that while P lies in Q1 (first quadrant), Q lies in Q2, R lies in Q3 and S lies in Q4.

Further, P and Q are reflection of each other in y-axis, Q and R are reflection of each other in x-axis, R and S are reflection of each other in y-axis and S and P are reflection of each other in x-axis.

Hence PQRS or midpoints of the sides of a rhombus ABCD form a rectangle.
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