Question

9)The head of a nail is circular as shown. The head of this nail has a diameter of 10 mm

Head of
the nail
Which measurement is closest to the area of the head of this nail in square millimeters?
A 314 mm²
B 15.7 mm²
C 31.4 mm²
D 78.5 mm²

Answer 1

Answer: Choice D) 78.5 mm²

Work Shown:

diameter = 10

radius = 5, which is half the diameter

area = pi*(radius)^2

area = 3.14*5^2

area = 78.5 mm²

The area is approximate since pi = 3.14 is approximate.

The notation mm² is shorthand for "square millimeters" or "square mm".