Selected MCQ

Current Question
An obtuse angle is ____.
  • A. < 90°
  • B. = 90°
  • C. > 90°
  • D. = 180°
Correct Answer: C
Explanation:
Between 90° and 180°.
Related Question 1
A tower of height 15 m makes an angle of elevation 60°. Find the distance from the base.
  • A. 5 m
  • B. 8 m
  • C. 10 m
  • D. 12 m
Correct Answer: C
Explanation:
tan60 = h/d → d = 15/√3 = 10 m.
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
The perimeter of a rectangle is 60 m. If its length is twice its breadth, its area is ____.
  • A. 160 m²
  • B. 180 m²
  • C. 200 m²
  • D. 220 m²
Correct Answer: C
Explanation:
Let breadth = x, then length = 2x; solving gives area = 200 m².
Related Question 5
The perimeter of a rectangle and a square is each 160 m. If the rectangle’s area is 100 m² less than the square's, what is the rectangle’s breadth?
  • A. 30 m
  • B. 40 m
  • C. 50 m
  • D. 60 m
Correct Answer: C
Explanation:
Solving for equal perimeters and an area difference yields breadth = 50 m.