Question

The area of a parallelogram whose sides are a = ( i + 2 j + 2 k) m and b = (2 i + 4 j + 5 k) m, is:

Answer 1

Answer:

ANSWER

If a and b be the adjacent sides of a parallelogram then the diagonals are

AC

=a+b,

BD

=b−a

∴ Unit vectors are

∣

∣

∣

∣

AC

∣

∣

∣

∣

AC

and

∣

∣

∣

∣

BD

∣

∣

∣

∣

BD

.

Area of parallelogram =∣a×b∣.

Ans.

7

1

(3i+6j−2k)×

(69)

1

(−i−2j+8k)=11

5

sq.units.