Question

7. Find the value of a if the area of the polygon formed by the points (8,6), (-a, 11), (a, 12) and (4,3) is 79 sq. units​

Answer 1

Answer:

Correct option is

C

18

Plotting the given points, as shown in the Figure as A, B, C, D we find AB is parallel to CD

∴ ABCD is a trapezium

Hence the area of ABCD

=

2

1

(AB+CD)× the distance between AB and CD ...(find distance using distance formula)

=

2

1

×(6+3)×4=18 square units.