6/7/17 Week 10 Wednesday daily sheet:
Surface area of spheres, cones, & pyramids
Daily aims:




1. I can calculate the surface area of spheres.
2. I can calculate the surface area of cones.
3. I can calculate the surface area of pyramids.
4. I can work “backwards” from the surface area of a sphere to a missing dimension.
Before lesson
1) Find these surface area formulas on your formula sheet:
During lesson
 sphere:
 cone:
 pyramid:
 right prism:
2) To the nearest square meter, what’s the surface area of a
sphere with radius 8.2 m?
3) Remember that the net of a cone has 2 parts—the circle
that is the base, and the triangle-like part with the curvy
bottom that forms the curved face of a cone.
Which part of the formula do you think goes to each part of
the net?
D. Stark 5/14/2017
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4) The variable “s” in the cone surface area
formula means slant height. On the picture
of the cone, indicate where you think
slant height might be.
5) Notice how the surface area formulas for a
pyramid and a right prism are similar and different.
See how they both use the perimeter (p) of the
Base. Look at the number of Bases (B) in the
formulas and whether the height is regular height
(h) or slant height (s).
6) What’s the surface area of the square pyramid
shown?
3 ½ in
3 in
D. Stark 5/14/2017
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6/7/17 Week 10 Wednesday daily sheet:
Surface area of spheres, cones, & pyramids
Before lesson
1) Find these surface area formulas on your formula sheet:
KEY
During lesson
 sphere: SA = 4  r2
 cone: SA =  r s +  r2
 pyramid: SA = ½ ps + B
 right prism: SA = ph + 2B
2) To the nearest square meter, what’s the surface area of a
sphere with radius 8.2 m?
SA = 4  r2
 4(3.14) (8.2)2
= 844.5344  845 m2
When you find the surface area of hemispheres
(as on the LEVEL 2 homework), remember to
add the flat circular part. Think of having to
cover all surfaces of a half grapefruit.
3) Remember that the net of a cone has 2 parts—the circle
that is the base, and the triangle-like part with the curvy
bottom that forms the curved face of a cone.
Which part of the formula do you think goes to each part of
the net? curvy triangle part:  r s
circle part:  r2
D. Stark 5/14/2017
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4) The variable “s” in the cone surface area
formula means slant height. On the picture
of the cone, indicate where you think
slant height might be.
5) Notice how the surface area formulas for a
pyramid and a right prism are similar and different.
See how they both use the perimeter (p) of the
Base. Look at the number of Bases (B) in the
formulas and whether the height is regular height
(h) or slant height (s).
6) What’s the surface area of the square pyramid
shown?
3 ½ in
p (perimeter) = 4(2 ½)
3 in
= 10 in
B (area of the square Base)
𝟐𝟓 2
= (2 ½ )2 =
in
𝟒
SA = ½ ps + B
𝟏
𝟐𝟓
𝟗𝟓
= (10) (3 ½) + ( ) =
=
𝟐
𝟒
𝟒
𝟐𝟑
𝟑
𝟒
in2
D. Stark 5/14/2017
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