Question

Plot the points O(0, 0), A(-3,0) and B(0,-6) on the graph paper and calculate the area of triangleOAB.

Answer 1

Answer:

9 square units.

Step-by-step explanation:

Let , O(0, 0), A(-3,0) and B(0,-6) be O(x₁,y₁), A(x₂,y₂) and B(x₃,y₃).

Area of triangle OAB

= $\frac{1}{2}$ |x₁   x₂    x₃  x₁ |

     |y₁    y₂   y₃  y₁ |

= $\frac{1}{2}$ |0  -3  0   0 |

    |0   0  -6   0 |

= $\frac{1}{2}$  | 0 + 18 + 0 - 0 - 0 - 0|

=  $\frac{1}{2}$ ×|18|

= $\frac{1}{2}$ × 18

= 9 sq. units