Question

The area of triangle OAB the co ordinates of whose vertices are (4,0) (0,-7) and O is the origin
​

Answer 1

Step-by-step explanation:

O(0,0)=(x1,y1)

A(4,0)=(x2,y2)

B(0,-7)=(x3,y3)

Area of triangle

=1 × {x1(y2-y3)+x2(y3-y1)+x3(y1-y2)}

2

= 1 × {0(0-(-7)+4(-7-0)+0(0-0)}

2

=1 × {0+(-28)+0}

2

= -14 unit ²

area of triangle=-14 unit ²