In the parallelogram ABCD, if vector AB + vector ad = vector ab - vector ad, then there must be A vector ad = vector 0 B ABCD is a square C ABCD is a rectangle D vector AB = vector 0 or vector ad = vector 0 | Math enthusiast | Mathematical art

In the parallelogram ABCD, if vector AB + vector ad = vector ab - vector ad, then there must be A vector ad = vector 0 B ABCD is a square C ABCD is a rectangle D vector AB = vector 0 or vector ad = vector 0

Vector AB + vector ad = vector ab - vector ad
Square AB * ad = 0
So the angle a = 90 degrees
So ABCD is a rectangle
The answer is C

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