Math in Focus 7B - Chapter 8 - 8.1: Recognizing Cylinders, Cones, Spheres, and Solids; 8.2: Finding Volume and Surface Area of Cylinders
cone
A cone has a circular base, a curved surface, and one vertex.
plane
A flat surface that extends infinitely in two directions.
cylinder
A solid cylinder has a curved surface and two parallel bases that are congruent circles.
sphere
A sphere has a curved surface. Every point on the surface is an equal distance from the center of the sphere.
Surface area of a cylinder =
Area of bases + Area of the curved surface 2πr² + 2πrh
hemisphere
If you slice a sphere in half, you will get two hemispheres.
The cross section of a sphere is a
circle
lateral surface
The curved surface of a cone.
slant height
The distance from the vertex to any point on the circumference of the base.
surface area
The sum of the area of the faces and curved surfaces of a solid figure.
How do you find the volume of a cylinder given its radius and height?
V = Bh V = πr² × h
cross section
When a flat plane slices through a solid
If given the volume and radius, can you find the height of a cylinder?
Yes, V = πr² × h
If you are given the surface area and height of a cylinder, can you find the radius?
Yes, area of the curved surface is 2πrh. Substitute in what you know and solve for h.
If you know the diameter of a cylinder's base, can you find the radius?
Yes, divide by 2 because the radius is half of the diameter.
volume
a measure of space enclosed in a solid figure
volume of a cylinder
area of the base x height B × h πr² × h
How do you square a number?
multiply the number by itself Examples: 2² = 2 × 2 = 4 3² = 3 × 3 = 9 4² = 4 × 4 = 16
If you slice through a square pyramid so that the cross section is parallel to its base, the cross section is a
square
If you slice through a square pyramid so that the cross section is perpendicular to the base, the cross section is a
triangle