Question

The area of a triangle with vertices A(5, 0), B(8, 0) and C(8, 4) in square units is

(a) 20 (b) 12 (c) 6 (d) 16

Answer 1

Area of the triangle $=\frac{1}{2}|x_1(y_2-y_3)+x_2(y_3-y_1)+x_3(y_1-y_2)|$

$=\frac{1}{2}|5(0-4)+8(4-0)+8(0-0)|$

$=\frac{1}{2}|-20+32|=6sq.units$