Bihar Police Constable Model Paper 5

GIVEN:
The vertices of the parallelogram = A(1, 2), B(a, -26), C(13, -14) and D(6, 14)
CONCEPT:
Using the distance formulae we will equate the parallel sides of the parallelogram.
FORMULAE USED:
D = √((x2−x1)²+(y2−y1)²)
CALCULATION:
AB = DC
⇒ {(a−1)2+(−26−2)2} = {(6−13)2+(14−(−14))2}
⇒ (a−1)2 + 784 = 49 + 784
⇒ (a−1)2 = 49
⇒ a - 1 = 7
∴ a = 8