The points , and are the vertices of a triangle. What is its area?
Answer and explanation
Correct answer: D. square units
- Step 1: Form two edge vectors: and .
- Step 2: Cross product: .
- Step 3: Its magnitude is , and the triangle area is half of it: .
Answer
square units.
Why not the others: is the area of the parallelogram; results from using the wrong vector; halves twice.
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