Question

What will be the perimeter of semicircle of diameter of 14 cm ? (Take \(\pi = \frac{22}{7}\))

• A. 77 cm
• B. 28 cm
• C. 36 cm
• D. 22 cm

Hint:

For a semicircle of radius \(r = 7\text{ cm}\), the curved part is always \(22\text{ cm}\) (since \(\frac{22}{7} \times 7 = 22\)).
Simply add the diameter to this value: \(22 + 14 = 36\text{ cm}\).
This is a standard dimension combination that appears frequently.

Answer 1

The Correct Option is C

Step 1: Work with the full circle first.
The diameter is 14 cm, and the full circumference of a circle of this diameter is \[ C = \pi d = \frac{22}{7} \times 14 = 44 \text{ cm} \]
Step 2: Take half of it for the curved part of the semicircle. \[ \text{Curved part} = \frac{44}{2} = 22 \text{ cm} \]
Step 3: Add the straight edge, which is the diameter itself. \[ \text{Perimeter} = 22 + 14 = 36 \text{ cm} \] \[ \boxed{36 \text{ cm}} \]