AlgebraMediumLongest side of a triangle from a perimeter
Algebra practice question
A triangle has sides of length x, x + 4, and 2x − 8 units, and its perimeter is 60 units. What is the length of the longest side?
Answer: 24
x + x + 4 + 2x − 8 = 4x − 4 = 60 → x = 16. The sides are 16, 20, and 24; the longest is 24.
Common wrong answers
- If you answered 14
- 14 comes from 4x + 4 = 60, mishandling the −8.
- If you answered 16
- 16 is x, the shortest side.
- If you answered 20
- 20 is the middle side.
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