What is the area of a triangle with vertices at (1,2), (5,8), and (10,3)?
Show answer & explanation
Correct answer: D
Explanation
Points = (1,2), (5,8), (10,3)
Area = 1/2 | x₁(y₂−y₃) + x₂(y₃−y₁) + x₃(y₁−y₂) |
= 1/2 | 1(8−3) + 5(3−2) + 10(2−8) |
= 1/2 | 1×5 + 5×1 + 10×(−6) |
= 1/2 | 5 + 5 − 60 |
= 1/2 | −50 |
= 25