Video Transcript
Using 3.14 as an approximation for
𝜋, find the area of the circle.
We begin by recalling that the
formula for finding the area of a circle is 𝜋𝑟 squared, where 𝑟 represents the
radius of the circle. From the figure, we identify that
the radius of this circle is 12 centimeters because we’ve been given the length of a
line segment connecting the center of the circle to a point on the circle’s
circumference.
So substituting 12 for 𝑟, we have
that the area of this circle is equal to 𝜋 multiplied by 12 squared. We must remember that it is just
the 12 we’re squaring. We’re not also squaring 𝜋. So this is equal to 𝜋 multiplied
by 144. We’re told that we should use 3.14
as an approximation for 𝜋. So evaluating 3.14 multiplied by
144 gives 452.16. The units for area are square
units.
So we found that the area of this
circle, which has a radius of length 12 centimeters, is approximately 452.16
centimeter squared.
