Post on 18-Jan-2016
Grade 8 Math ChartBy: Brandon Wright
Perimeter
The distance around a 2 dimensional shape
Square P= 4s
Rectangle P= 2l+2w or P= 2 (l + w)
What is the perimeter of this rectangle?
8 in.
2 in.
Answer- 20 in.
What is the perimeter of this square?
4 in.
4 in.
Answer- 16 in.
Circumference
The perimeter of a circle
Circle C= 2πr or C= πd
What is the circumference of a circle if the diameter is14 cm.?
Answer- 42 cm.
AreaThe area is the surface of an object
measured in squared units
Square A= s2
Rectangle A= lw or A= bh
Triangle A= 1/2 bh or A= bh/2
Area Continued
Trapezoid A= 1/2 (b1 + b2) or A=(b1+b2)h/2
Circle A= πr2
What is the area of this square?
7 in.
7 in.
Answer- 49 in2
What is the area of this rectangle?
8 cm.
5cm.
Answer- 40 cm2
What is the area of this triangle?
9 in.
4 in. Answer- 18 in2
What is the area of this trapezoid if the height is 9 cm.?
11 cm.
15 cm. Answer- 117 cm2
What is the area of a circle if the radius is 12 cm.?
Answer- 452 cm2
P represents the perimeter of the base of a three dimensional figure.
B is the area of the base of a three dimensional figure.
Surface Area
The extent of a 2D surface enclosed in a boundary
Cube 6s2
Prism (Lateral) Ph
Prism (Total) Ph + 2B
Pyramid (Lateral) 1/2 PL
Surface Area Cont.
Pyramid (Total) ½ Pl + B
Cylinder (Lateral) 2πrh
Cylinder (Total) 2πr(h + r)
What’s the surface area of this cube if one side is 8 in. long?
8 in.
Answer- 384 in.
What is the surface area of this lateral prism if the height is 5 cm. and the perimeter of the base is 10 cm.?
Answer- 50 cm.
What is the surface area of this total prism if the perimeter of the base is 10 cm. the area is 16 cm. and the height is 18 cm.?
Answer- 212 cm.
What is the surface area of this lateral prism if the base’s perimeter is 10 in. and the length is 8 in.?
Answer- 40 in.
What’s the surface area of a total pyramid if the area of the base is 16 in. the perimeter is 16 in. and the length is 8 in.?
Answer- 72 in.
What’s the surface area of a lateral cylinder if the radius is 8 cm. and the height is 10 cm.?
Answer- 240 cm.
What is the surface area of a total cylinder if the height is 10 in. and the radius is14 in.?
Answer- 2016 in.
Volume
The amount of space an object takes up
Cube S= 6s2
Prism S= Ph
Pyramid S= ½ Pl
Cylinder S= 2πrh
What is the volume of a prism that the base area is 16 in. and the height is 12 in.?
Answer- 192 in3
What is the volume of a cylinder if the area of the base is 36 cm. and the height is 14 cm.?
Answer- 504 cm3
What is the volume of a pyramid if the area of the base is 16 in. and the height is 9 in.?
Answer- 48 in3
What is the volume of a cone if the area of the base is 9 cm. and the height is also 9 cm.?
Answer- 27 cm3
What is the volume of this sphere if the radius is 5 in.?
Answer- 500 in3
Pi
Ratio of a circumference of a circle of its diameter
3.14 or 22/7
What is the area of a circle if the diameter is 6 in. and the formula is πr2?
Answer- 108 in2
Pythagorean Theorem
A theorem that the square of the hypotenuse of a right triangle is equal to the sum of the squares of the other two sides
a2 + b2= c2
If two angles in a triangle are 100o and 35o than what is the measure of the third angle?
Answer- 45o
Simple Interest Formula
When you borrow money and need to pay it back
I= prt
P = $15,000R = 15%T = 3 yearsFind I.
Answer- $6750
Linear Equation
An equation whereby letters represent real numbers and whose graph is a line
4y = 2(x + 2y)
x= 4(3y) – 12
If y is 3, then what is x?
Answer- 24
Function
The idea that one quantity completely determines another quantity
x {2,4,6,8}Find the y values if the function is
x2=y.
y {4,8,12,16}
Function Notation
A notation that describes a function
f(x) = 2x 2 + 3x + 4
Domain
The x point
What is the domain? (8, 6)
Answer- 8
Range
The y point
(8, 6)
Whats the range?
Answer- 6
Ratios
Comparing a number to another number like 3:4, 3 to 4, or 3/4
The ratio of boys to girls is 5:3 so if there is 30 girls how many boys are there? What is the new ratio?
Answer- 18; 30:18