Question

Two adjacent sides of a triangle are represented by the vectors a = 3i + 4j and b = -5i + 7j. The area of the triangle is

A. 41 sq units

B. 37 sq units

C. 41/2 sq units

D. none of these

Answer 1

Answer is : C. 41/2 sq units

Given - Two adjacent sides of a triangle are represented by the vectors a = 3i + 4j and b = -5i + 7j

To find – Area of the triangle

Formula to be used -

Tip – Area of triangle = 1/2 |a x b| and magnitude of a vector p = xi + yj + zk is given by

i.e. the area of the parallelogram = 41/2 sq. units