Selected MCQ

Current Question
The perimeter of a semicircle is 144 cm. What is the radius?
  • A. 25 cm
  • B. 28 cm
  • C. 30 cm
  • D. 35 cm
Correct Answer: B
Explanation:
Perimeter = πr + 2r; solving gives r = 28 cm.
Related Question 1
The radius of a semicircle is 6.3 cm. Find its perimeter.
  • A. 35.4 cm
  • B. 32.4 cm
  • C. 32 cm
  • D. 30 cm
Correct Answer: B
Explanation:
Perimeter = πr + 2r.
Related Question 2
A sector of radius 21 cm and angle 135°. Find perimeter.
  • A. 91.5 cm
  • B. 93.5 cm
  • C. 94.5 cm
  • D. 92.5 cm
Correct Answer: A
Explanation:
Perimeter = arc + 2r.
Related Question 3
The perimeter of a triangle is 28 cm, and its inradius is 2.5 cm. Find its area.
  • A. 25 cm²
  • B. 42 cm²
  • C. 49 cm²
  • D. 35 cm²
Correct Answer: D
Explanation:
Area = r × semi-perimeter = 2.5 × 14 = 35 cm².
Related Question 4
Two circles have a radius relation. Area of the square is 196 cm². Find radius.
  • A. 12π
  • B. 16π
  • C. 24π
  • D. 32π
Correct Answer: C
Explanation:
Side=14, radius=7×? → area relation.
Related Question 5
The slant height of a cone is 12 cm, and the radius is 4 cm. Find the curved surface area.
  • A. 74π cm²
  • B. 36π cm²
  • C. 48π cm²
  • D. 24π cm²
Correct Answer: C
Explanation:
CSA = πrl = π×4×12.