The sides of a rectangular field are 198 m and 175 m long. Its area is equal…
2026
The sides of a rectangular field are 198 m and 175 m long. Its area is equal to the area of a circular field.
What is the perimeter (in m) of the circular field? Take π = 22/7.

Answer: B. 660 — ConceptWhen two plane figures have equal areas, equate their area formulas. For a rectangle, A = l × b; for a circle, A = πr2, and the circle’s perimeter…
- A.
658
- B.
660
- C.
667
- D.
654
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Show answer & explanation
Correct answer: B
Concept
When two plane figures have equal areas, equate their area formulas. For a rectangle, A = l × b; for a circle, A = πr2, and the circle’s perimeter (circumference) is C = 2πr.
The shared area determines r first; the circumference is then obtained from that radius.
Application
Calculate the rectangle’s area: A = 198 × 175 = 34,650 m2.
Equate the areas: πr2 = 34,650. With π = 22/7, r2 = 34,650 × 7/22 = 11,025.
Take the positive square root because radius is a length: r = √11,025 = 105 m.
Calculate the circumference: C = 2 × 22/7 × 105 = 660 m.
Cross-check
For r = 105 m, the circle’s area is (22/7) × 1052 = 34,650 m2, exactly equal to 198 × 175. Therefore, the required perimeter is 660 m.