Math Formulas

Question 1

Square - Perimeter

Answer 1

P = 4s

Multiply any one side by four

Question 2

Square - Area

Answer 2

A = s^2

Square one side

Question 3

Cube - Volume

Answer 3

V = lwh

length * width * height

AKA prism, rectangles

Question 4

Rectangle - Area

Answer 4

A = lw

length * width

Question 5

Rectangle - Perimeter

Answer 5

P = 2l + 2w

multiply the length by 2 & width by 2 & add

Question 6

Prism - Surface Area

Answer 6

A = 2(lw + wh + lh)

Question 7

Circle - Circumference

Answer 7

C = 2πr

OR

C = πd

depending on your info.

two radii equal the diameter, so 2r = d

Question 8

Circle - Area

Answer 8

A = πr^2

Question 9

Cylinder - Area

Answer 9

Lateral area (side) = 2πrh

=> 2πradius*height

total area = 2πrh + 2πr^2

=> this combines the lateral area plus the area of the two circles (which is why the area is multiplied by 2)

Question 10

Cylinder - Volume

Answer 10

V = πr^2h

– it’s just circle area times height

Question 11

Triangle - Pythagorean Theorem

Answer 11

a^2 + b^2 = c^2

a & b are legs, c is hypotenuse

Question 12

Triangle - Area

Answer 12

A = 1/2bh

1/2 * base * height

Question 13

Pyramid - Volume

Answer 13

V = 1/3bh

volume = 1/3 * b * height

Question 14

Trapezoid - Area

Answer 14

A = 1/2(b + b’)h

area = 1/2 (top base + bottom base) * height

Question 15

Parallelogram

Answer 15

A = bh

Question 16

Distance

Answer 16

D = rt

– multiply the rate (r) by the time (t) to find the distance (D)

r = D / t
OR
t = D / r

Question 17

Slope of a Line

Answer 17

y = mx + b

aka: y = slope*x + y-intercept

mx => slope
x & y => pair of coordinates
b => y-intercept, where the line passes through the y-axis

Question 18

Calculating slope (rise over run)

Answer 18

m = y2 - y1 / x2 - x1

OR

slope = rise / run

(2, 3) (4, 6)

(6 - 3) / (4 - 2) = 3 / 2

Question 19

Average

Answer 19

AVG = sum of numbers / # of terms

aka “mean”

Question 20

Mean, Median, Mode, Range

Answer 20

Mean ==> average

Median ==> middle # of data set

Mode ==> most common number of a data set

Range ==> the difference between the highest # and the lowest #

Question 21

Probability

Answer 21

probability of an event occurring = # of successful outcomes / total # of possible outcomes

Question 22

Percent Increase

Answer 22

[(final amount - original amount) / original amount] * 100%

Question 23

Percent Decrease

Answer 23

[(original amount - final amount) / original amount] * 100%

Question 24

Hexagon - Area

Answer 24

A = (3√3 / 2)a^2

a = one side of hexagon

sum of all angles = 720 => 720/6 = 120

Question 25

Pentagon - Area

Answer 25

A = 1/4 (√5(5 + 2√5)a^2

Note: “5(5 + 2√5) are all under the square root

a = side

sum of all angles = 540 => 540/5 = 108

Question 26

Octagon - Area

Answer 26

A = 2(1 + √2)a^2

a = side

sum of all angles = 1080 => 1080/8 = 135

Question 27

Decagon - Area

Answer 27

A = (5/2)a^2 * √5 + 2√5

Note: “5 + 2√5” are all under square root

a = side

sum of all angles = 1440 => 1440/10 = 144