Formulas Flashcards
Distance
rate x time=rt=d
Circles
Lenght of an arc
(x/360)[2(3.14 or pi)r]
x=central angle of the arc
Circle
Area of sector
(x/360) [(pi)r*r]
x=central angle of the sector
Combination
Number of combinations
N!\R!(N-R)!
N= number of total items
R= number of items being choosen
Permutations
number of permuttation
N!(N-R)!
N= Number of items
R= Number of items being choosen
Lenght of a Diagonal of a Cube
s(2to the square root)
Length of a Diagonal of a Cube
s(3 square root)
Number of Diagonals for a Convex Polygon with
N Sides
N(N-3)\2
Sum of the Measures of the Interior Angles of a Regular Polygon with
N Sides
(N-2)180
Pythagorean Theorem: (Can be used with
all right triangles)
(a*a)+(b*b)=(c*c)
Geometric Mean
a\x=x\b then (x*x)=ab and x=ab squared root
Regular Polygon
measure of a central angle=360\n; n= number of side of the polgyon measure of a vertex angle=180-360\n;n= number of side of the polgyon
Ratio of Two Similar Figures
If the ratio of the measures of corresponding side lengths is
A:B,then the ratio of the perimeters isA:B, the ratio of the areas is
A2 :B2 and the ratio of the volumes is A3 :B3
Difference of Two Squares
a2-b2=(a-b)(a+b)
Greatest Common Factor (GCF)
Multiply the two numbers and divide by the Least Common Multiple (LCM)
Example: to find the GCF of 15 and 20, multiply 15×20 = 300,then divide by the LCM, 60. The GCF is 5
consececutive
n(n+1)/2
