ASVAB (Armed Services Vocational Aptitude Battery)Mathematics Knowledge (MK)Medium
A maintenance crew is repainting a large circular helipad. If the diameter of the helipad is 30 meters, what is the area of the helipad to the nearest square meter? (Use π ≈ 3.14)
- A471 m²
- B942 m²
- C236 m²
- D707 m²
Show answer & explanationAnswer & explanation
Correct answer: D. 707 m²
First, find the radius: radius = diameter / 2 = 30 m / 2 = 15 m. Then, use the formula for the area of a circle: Area = π * r². So, Area = 3.14 * (15 m)² = 3.14 * 225 m² = 706.5 m². Rounded to the nearest square meter, the area is 707 m².
Why the other options are wrong
- A. Possible error in squaring the radius or wrong formula (e.g., πd).
- B. Used diameter instead of radius, or other significant error.
- C. Incorrect radius or formula (e.g., perimeter calculation).
Area of a Circle
The area of a circle is the measure of the two-dimensional space enclosed within its boundary. It is calculated using the radius.
- Formula: Area = π * r² (where r is the radius).
- If given diameter (d), radius r = d/2.
- Units for area are square units (e.g., m², ft²).
Memory trick: Radius 'R'ules for 'A'rea.