The area (in sq units) of the triangle formed by joining the points (3, 0), (0, 6) and (-5, 0) is

24

Area of the triangle having vertices on the points (x₁, y₁), (x₂, y₂) and (x₃, y₃) = (1/2) × [x₁ (y₂ - y₃) + x₂ (y₃ - y₁) + x₃ (y₁ - y₂)]

Area of the triangle with vertices (3, 0), (0, 6) and (-5, 0)

= (1/2) × [3(6 - 0) + 0(0 - 0) + (-5)(0 - 6)]

= (1/2) × [18 + 0 + 30]

= (1/2) × 48 = 24