the difference between prisms & pyramids. “it’s all about how you slice it!”
TRANSCRIPT
The difference between prisms & pyramids.
“It’s all about how you slice it!”
Pyramids and prisms are specific kinds of polyhedra.
The word polyhedra is the plural form of polyhedron.
A polygon is a 2-dimensional shape.
A polyhedron is a 3-dimensional shape.
Presto! A triangular prism!
Presto! A triangular pyramid!
Presto! A square prism!
Presto! A square pyramid!
A prism is made of congruent shapes.
A pyramid is made of similar shapes that get smaller and
smaller.
If you know the names of common polygons, then naming a prism or pyramid will be easy
for you.
Look at the polygon on the bottom of the shape.
This polygon is a rectangle.
This shape is a rectangular prism.
This shape is a rectangular pyramid.
This is a pentagon.
This is a pentagonal prism.
This is a pentagonal pyramid.
This is an octagon.
This is an octagonal prism.
This is an octagonal pyramid.
If you know the common polygons and if you know the
difference between a prism and a pyramid, naming these shapes is
easy.
The only unique name that you have to remember is the “cube.”
A cube is a specific kind of rectangular prism.
A rectangular prism that has 6 congruent faces is called a cube.
A rectangular prism that has 6 congruent faces is called a cube.
A rectangular prism that has 6 congruent faces is called a cube.
A rectangular prism that has 6 congruent faces is called a cube.
A rectangular prism that has 6 congruent faces is called a cube.
A rectangular prism that has 6 congruent faces is called a cube.
• A sphere is the set of all points in space that are the same distance from a point, the center of the sphere.
• A hemisphere is created when a sphere is cut in half.
Surface Area of a Sphere
• Surface area = 4 π (radius)2
• S = 4 π r2
C Radius
Find the Surface Area of a Sphere• Find the surface area of the sphere. Round your
answer to the nearest whole number.
a.
The radius is 8 in.
24S r24 (8)
8 in. 2804644 in
Find the Surface Area of a Sphere• Find the surface area of the sphere. Round your
answer to the nearest whole number.
b.
The radius is 5 cm.
24S r24 (5)
10 cm.2314254 cm
Volume of a Sphere
• Volume = 34
3r
34
3V r
radiusC
Find the Volume of a Sphere• Find the volume of the sphere. Round your answer to the
nearest whole number.
a.
32(3.14)
3
34
3V r
34(2)
3
4(8)
3
32
3
334 .ft
2 ft.
Find the Volume of a Sphere• Find the volume of the hemisphere. Round your answer to
the nearest whole number.
b. A hemisphere has half the volumeof a sphere.
31 4
2 3V r
31 4
(5)2 3
250
3
3262 .in
a 5 in.
Find the Volume of a Sphere• Find the volume of the sphere. Round your answer to the
nearest whole number.
a.34
3V r
34(6)
3
4(216)
3
2883905 .in
6 in.
AssignmentWorksheet 24 and 26 in packet