-
A copper wire is bent in the shape of a square of area 81cm2. If the same wire is bent in the form of a semicircle, the radius (in cm) of the semicircle is (Take π = 22/7)
-
- 16
- 14
- 10
- 7
- 16
Correct Option: D
Using Rule 10 and 14,
Side of a square = √81 = 9 cm
∴ Length of the wire = 4 × 9 = 36 cm.
∴ Perimeter of semi-circle = (π + 2)r where r = radius
| ⇒ |  | + 2 |  | r = 36 cm | |
| 7 |
| ⇒ | r = 36 | |
| 7 |
| ⇒ r = | = 7 cm | |
| 36 |
