Question

On a coordinate plane, triangle L M N has points (1, negative 1), (3, 2), and (1, 3). An altitude is drawn from point M to point P on side N L.
What is the area of triangle LMN?

3 square units
4 square units
6 square units
8 square units

Answer 1

4 square units

Reason: NL is between (1, −1) and (1, 3), so base = 4. The altitude from M(3,2) to line x = 1 has length 3 − 1 = 2. Area = 1/2·base·height = 1/2·4·2 = 4.