UPSC NDA I 2021 Mathematics Solved Paper

Concept
ABCD is a parallelogram P,Q,R and S are mid-points of AB,BC,CD and DA respectively. Then PR and SQ bisect each other.
Calculation:
Applying the mid-point theorem,
‌

x+0

2

=‌

5−3

2

⇒x=2
‌

y−4

2

=‌

4+2

2

⇒y=10
So, the 4th coordinate is (2,10)