Question
Question: Area of $\triangle ABC$ is...
Area of △ABC is

A
82
B
42
C
22
D
62
Answer
42
Explanation
Solution
The vertices of the triangle are A(0,0), B(2,22), and C(2,−22). The base BC is a vertical segment with length ∣22−(−22)∣=42. The height of the triangle from vertex A to the base BC is the perpendicular distance from A(0,0) to the line x=2, which is 2. The area of △ABC=21×base×height=21×(42)×2=42.