Presented by : Anggun Nugraha Oktaviani Deti Nur Karina Fiona Salfadilla Rifda Nadifah Umroh Indah Lestari

2. CONE

3. CONE
The net The examples in daily life

5. 2 ∏r
Area of Circle
∏l2
l
l
h
r
r
B=∏ r
2 C= 2 ∏ r C= 2 ∏ l
B = Base area of circle
C = Circumference of circle
h = height of cone
r = radius of circle
l = slant height of cone

7. The example of cones in daily life
CONES ANAK KRAKATAU
MOUNTAIN
TRAFFIC CONE

8. The Formula of Cone
 Lateral Area / Curved Surface : 2 ∏r
l
l
h
r Area of Circle
∏l2
r
C= 2 ∏ r C= 2 ∏ l
area of sector Perimeter of sector / perimeter of cone’s base
B=∏ r
2
=
area of circle perimeter of circle
area of sector 2∏ r
=
∏l2 ∏l2 2∏ l 2
area of sector r ∏l2
=
∏l 2
l
Area of sector = ∏rl

9.  Total Surface Area :
T = Area of sector + Area of cone’s base
T = Cs + Ba
T = (∏ r l) + (∏ r2 )
 Volume Of Cone :
V= Ba . h
V= (∏ r2 ) h

10. Example
A cone has a base diameter of 10 cm and height of 12 cm. For
∏ = 3.14
Find : a. the curved surface area
b. the base area
c. the surface area
d. the volume
h = 12cm
r = 5cm

11. Solution
Given that : r = 5 cm a. The curved surface area :
h = 12 cm Cs = ∏ r l
∏ = 3. 14 = 3.14 x 5 cm x 13 cm
= 204.1 cm2
l 2 = h2 + r 2 So, the curved surface area of cone is
l = 204.1 cm 2
l = b. The base area :
Ba = ∏r 2
l =
= 3.14 x 5 cm x 5 cm
l = l = 13 cm = 78.5 cm 2
So, the slant height of cone is So, the base area of cone is 78.5 cm 2
13 cm.

12. c. the surface area = ?
the surface area = Cs + Ba
= 204.1 cm2 + 78.5 cm2
= 285.6 cm2
so, the surface area of cone is 285.6 cm2

13. d. volume = Ba . h
= 78.5 cm2 x 12 cm
= 314 cm3
So, the volume of cone is 314 cm3

14. EXERCISE
Given that the curved surface
of cone beside is 550 cm2 and
the radius is 7 cm
Find :
a. The slant height
b. The surface area of the
cone
c. The height of cone