Area scales by k2: the SAT math trap
Short answer: Lengths scale by k, area by k², volume by k³.
The trap, in one question
A triangle has area 8. Every side length is tripled. What is the area of the new triangle?
Tempting answer: 24 (8 × 3)
Correct answer: 72 (8 × 32)
How to spot it in 3 seconds
Lengths scale by k, area by k², volume by k³.
FAQ
What is the area scales by k2 trap on the SAT?
Example: A triangle has area 8. Every side length is tripled. What is the area of the new triangle? The tempting answer is 24 (8 × 3); the correct answer is 72 (8 × 32).
How do you avoid the area scales by k2 trap?
Lengths scale by k, area by k², volume by k³.
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