9th Class
Mathematics
Coordinate Geometry
Question Bank
Co-ordinate Geometry
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