question_answer

The area of a triangle with vertices \[\mathbf{A}\left( \mathbf{0},\mathbf{6} \right),O\left( \mathbf{0},\mathbf{0} \right)\]and \[\mathbf{B}\left( \mathbf{7},\mathbf{0} \right)\]is:

A)  8 sq. units                 

B)  13 sq. units

C)  21 sq. units     

D)  40 sq. units

Correct Answer: C

Solution :

(c):   Clearly,\[OA=6\]units \[OB=7\]units \[\therefore \] Area of \[\Delta OAB\] \[=\frac{1}{2}\times OA\times OB\] \[=\frac{1}{2}\times 7\times 6=21\]sq. units