Perimeter from the area — Mensuration Aptitude Question
Perimeter from the area: The area of a square is 169 cm². What is its perimeter? Answer and worked solution on CodeKairo.
- Topic: Mensuration
- Section: Quantitative Aptitude
- Difficulty: Easy
- Time target: 45 seconds
Question
The area of a square is 169 cm². What is its perimeter?
Options
- 26 cm
- 39 cm
- 52 cm
- 676 cm
Show the answer and the worked solution
Correct answer: C. 52 cm
Worked solution
- Side = √169 = 13 cm.
- Perimeter = 4 × 13 = 52 cm.
Answer: 52 cm.
The idea
Route through the side length. Area gives the side, and the side gives every other measurement of the square.
Shortcut. Perimeter = 4√area; 169 = 13², so 4 × 13 = 52 cm.
Common trap. "676 cm" — multiplying the area 169 by 4 instead of first taking its square root.