1. 12.3 Surface Area of Circular Solids
cylinder
cone
sphere

2. Cylinder: base is a circle
Contains 2 congruent parallel bases.
Right circular cylinder perpendicular line from center to each base.
Net: h r

3. Net:
T113: LAcyl = Ch
C = circumference
h= height
Lateral area: A = bh
b = circumference (2πr or πd) h b h r

4. Total area: TA = 2(πr2) + 2πrh
Lateral area: A = bh
b = circumference (2πr or πd)
Net: b h h r

5. Find the surface area of the following cylinder:
7cm
TA = 2(πr2) + 2πrh
10cm

6. l
Cone: base is a circle
Slant height and lateral height are the same.
l = slant height
Cone will mean a right cone where the altitude passes through the center of the circular base.

7. l = slant height T114: LA = ½ Cl = πrl Net: C = circumference
r = radius

8. Find the surface area of the cone.
The diameter is 10
The slant height is 6
TA = LA + Abase
= πr2 + πrl

9. Sphere: special surface area formula.
NO lateral edges
No lateral area
Proof will come later – requires limits.
Postulate: TA = 4πr2
Radius of the sphere!

10. Find the total surface area of the following shape
Find the total surface area of the following shape. Hint: just what you see!