Radha made a semicircular design in her notebook with radius 5 cm. Find its…
2026
Radha made a semicircular design in her notebook with radius 5 cm. Find its perimeter in terms of π.
Answer: D. (5π + 10) cm — ConceptThe perimeter of a semicircle includes both the curved half-circumference and the straight diameter. For radius r, the curved length is πr and the…
- A.
(5π + 8) cm
- B.
(5π + 14) cm
- C.
(5π + 12) cm
- D.
(5π + 10) cm
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Show answer & explanation
Correct answer: D
Concept
The perimeter of a semicircle includes both the curved half-circumference and the straight diameter. For radius r, the curved length is πr and the diameter is 2r, so the total perimeter is P = πr + 2r.
Application
The radius is r = 5 cm.
Curved length = πr = π × 5 = 5π cm.
Diameter = 2r = 2 × 5 = 10 cm.
Therefore, P = 5π + 10 cm.
Cross-check
The result contains one curved part, 5π cm, and one straight part, 10 cm. These are exactly the two boundary parts of a semicircle.
Result: (5π + 10) cm.