area of

2. What is the area and
circumference of a
circle?

3. AREA OF A CIRCLE
The area of a circle is the amount of space within a
circle and the circumference of a circle is the distance
around the edge of the circle.

4. The area of the circle is the
measure of the space or region
enclosed inside the circle.
In simple words, the area of a
circle is the total number of
square units inside that circle.

5. THE UNIT OF
MEASUREMENT CAN BE
EXPRESSED AS
square meter (m²)
square centimeter (cm²)
square decimeter (dm²)
etc…

8. A street sweeper is working on her area when
she noticed an open manhole. For the safety of
the pedestrians, she knows that she must find a
cover for this manhole. She found an old
manhole cover in their stock room that has a top
surface area of 3000 sq. cm. If the diameter of
the open manhole is 60 cm, would the old
manhole cover be useful?

9. To know if the street sweeper would
be able to use the cover that she
found in their stock room, we have
to compare the area of the manhole
to the area of the cover.

10. Given that the diameter of the manhole
is 60 cm, we know that the radius is 30
cm.
πr
Given: 60 cm
r = ½d
R = 60/2
= 30cm

11. A= r x r x π
A = 30 cm x 30 cm x
3.14
A = 900 cm² x 3.14
A = 2826 cm²
The area of the open
manhole is 2826 cm²
A= πr²
A = 3.14 x 30² cm
A = 3.14 x 900 cm²
A = 2826 cm²
The area of the open
manhole is 2826 cm²

12. 1.r = 8 cm
2.d = 12 in

13. 1) 40mm
2) 2.8 m
3) 15 units
4) 9 cm
5) 15.3 cm
πr

14. REMEMBER!
The area of the circle is the measure of the
space or region enclosed inside the circle. In
simple words, the area of a circle is the total
number of square units inside that circle.
To calculate the area of a circle, π (Pi) times
the Radius squared: A = π r² or, when you
know the Diameter: A = π (D/2)² The radius
of any circle is always half the diameter.