If the circumference of a circle is increased from 4π to 8π, then its area is:
2013
If the circumference of a circle is increased from 4π to 8π, then its area is:
- A.
tripled
तीन गुना
- B.
halved
आधा
- C.
quadrupled
चार गुना
- D.
doubled
दो गुना
Attempted by 3 students.
Show answer & explanation
Correct answer: C
First, find the initial radius using C = 2πr. For 4π, r=2.
The initial area is π(2)² = 4π. Next, find the new radius for 8π, which is r=4.
The new area is π(4)² = 16π.
Comparing the areas, 16π / 4π = 4, so the area quadruples.