Question

The area of the triangle whose vertices are given by the coordinates (1, 2), (-4, -3) and (4, 1) is:

• A. 7 sq. units
• B. 20 sq. units
• C. 10 sq. units
• D. 14 sq. units

Answer 1

Answer:

C. 10 sq. units

Area of triangle = ½ [x1 (y2 - y3) + x2 (y3 - y1) + x3 (y1 - y2)] whose vertices are (x1, y1), (x2, y2) and (x3, y3) Area of triangle = (1/2) × [1(-3 – 1) + (-4) (1 – 2) + 4{2 – (-3)}] = (1/2) × {(-4) + 4 + 20} = 20/2 = 10 sq. units