Chapter 10
Natalie Taylor
**Don't Forget**
Labels--in^2, m^3, etc.
All Formulas:
Area
Surface Area
Pyramid : B+1/2*P*l
Cone : Pi*r^2+Pi*r*l
Sphere: S=4*pi*r^2
Volume
Pyramid : B+1/2*P*l
Cone: Pi*r^2+Pi*r*l
Sphere: V=4/3*pi*r^3
Extra
-E+2=F+V (find out if edges, vertices, and faces are correct on a 3-dimensional object)
Notes:
-capital letters in formulas are usually associated with area
10.1: Areas of parallelograms and trapezoids
Vocabulary
- The base if a parallelogram is the length of any one of its sides
- The height of a parallelogram is the perpendicular distance between the base and the opposite side.
- The base of a trapezoid are its two parallel sides
- The height of a trapezoid is the perpendicular distance between the bases
Paralellograms
- The area of a parallelogram is the product of the base and the height.
- The formula for a parallelogram is A=bh.
- The b stands for the base, the length of any one of its sides.
- The h is the height, and is always perpendicular to the base.
Trapezoids
- The area of a trapezoid is one half the product of the sum of the bases and the height.
- The formula is A=1/2(b1+b2)h.
- b1 stands for the 1st base.
- b2 is the 2nd base.
- The h is always perpendicular to b1 and b2.
- The bases are parallel.
Practice Problems
Parallelogram:
h=3cm b=5cm
A=b*h
A=5*3
A=15cm squared
Trapezoids:
b1=2mm b2=4mm h=5mm
A=1/2(b1+b2)h
A=1/2(2+4)5
A=1/2*30
A=15mm
Real Life:
The Winslow House in River Forest, Illinois, was designed by Frank Lloyd Wright. The front part of the roof is a trapezoid. What is the area is b1=31ft b2=77ft and h=25ft?
Answer: 1,350ft squared
10.2: Areas of circles
Area of a circle: A=pi*r2
Vocab:
A circle is the set of all points in a plane that are the same distance from a fixed point
Practice:
Circle
r=5
A=pi*5squared
A=78.53981634...
Real Life:
Todd puts in a hot tub in his back yard. He needs to figure out how much space it will take up. The diameter is 3ft. Find the area.
Answer: 7.068583471ft... or 8ft
10.3 Three-Dimensional Figures
Formulas:
-E+2=F+V (find out if edges, vertices, and faces are correct on a 3-dimensional object)
-E= edges
-F= faces
-V= vertices
Solid: A three-dimensional figure that encloses a part of space.
Polyhedron: A solid that is enclosed by polygons.
Prism: A polyhedron, has two congruent .bases that lie in parallel planes. The other faces are rectangles.
Pyramid: Is a polyhedron, has one base, and other faces are triangles
Cylinder: A solid with two congruent circular bases that lie in parallel planes.
Cone: A solid with one circular base.
Sphere: A solid formed by all points in space that are the same distance from a fixed point called the center.
Edge: The segments where faces of a polyhedron meet.
Vertex: A point where three or more edges meet. (Plural of vertex is vertices.)
Notes:
-solid shape (prism, pyramid) is defined by its base
ex: rectangular prism, rectangular pyramid
-lateral area is the area of the sides (everything but the base/bases)
10.4 Surface Area of prisms and Cylinders
Surface area of a prism: S=2B+Ph
Surface area of a cylinder: 2B+Ch or 2*pi*r2 + 2*pi*r*h
Lateral surface area= 2*pi*r*h
Vocab:
(S) is surface area
(2B) is the sum of twice the area of the base
(Ph) is the product of the base's perimeter and the height
(Ch) is the product of the base's circumference and the height
A prism is a polyhedron that have two congruent bases that lie in parallel planes and the other faces are rectangles.
A cylinder is a solid with two congruent circular bases that lie in parallel planes
Practice:
Triangular Prism
B=.5*10*12cm
P=13+13+10cm
h=15cm
A+2(.5*10*12) + (13+13+10)15
A=660cm
10.5 Surface area of Pyramids and Cones
Surface area of a pyramid: S=B+.5*Pl
Surface area of a cone: S=pi*r2* + pi*r*l
Curved lateral surface of a cone: A= pi*r*l
Vocab:
slant height of a regular pyramid is the height of a lateral face, that is, any face that is not the base
(.5Pl) is one half of the product of the base perimeter and the slant height
Practice:
rectangular pyramid
B=27.7
P=24
l=6
S=B+.5*Pl
S=27.7+.5(24)(6)
S= about 99.7
Real Life!
Bob works at an ice cream shop. He decided to some extra chocolate to dip a cone in. Bob's not sure if he has enough chocolate so he want's to calculate the surface area of the cone. If the radius is 2in and the slant height is 4in, then what is the surface area?
Answer:37.69911184in squared or 37in squared
10.6 Volumes of Prisms and Cylinders
Formula:
Volume of a Prism: V=B*h
Volume of a Cylinder: V=B*h or V=pi*r2*h
Vocab:
The volume of a solid is a measure of the amount of space it occupies.
Practice:
prism
l=12
w=8
h=2
V=B*h
V=12(8)(2)
V=192
10.7 Volume of Pyramids and Cones
Formula:
Volume of a Pyramid: V= 1/3*B*h
Volume of a cone: V=1/3*B*h or V=1/3*pi*r2*h
Vocab:
Pyramids are polyhedrons that have one base. The other faces are triangles
A cone is a solid with one circular base
Practice:
pyramid
B=30squared
h=15
V=1/3*B*h
V=1/3(30squared)(15)
=4500