GCSE Maths Formulae
Surface area of cylinder
(2 x π x r x h) + (2 x π x r2)
Sum of interior angles (irregular polygons)
(number of sides - 2) x 180
Surface area of cone
(π x r x l) + (π x r2)
Area of trapezium
1/2 x (total of parallel sides) x H
Area of triangle
1/2 x B x H
Volume of pyramid
1/3 x Base Area x H
Volume of cone
1/3 x π x r2 x H
Interior angle
180 - Exterior angle
Sum of exterior angles (irrregular polygons)
360
Exterior angle
360 / number of sides
Surface area of sphere
4 x π x r2
Volume of sphere
4/3 x π x r3
Angles in a triangle
Add up to 180
Angles on a straight line
Add up to 180
Supplementary angles (U angles)
Add up to 180
Angles in a quadrilateral
Add up to 360
Angles round a point
Add up to 360
What is a acute angle?
An angle between 0 and 90
What is a reflex angle?
An angle between 180 and 360
What is a obtuse angle?
An angle between 90 and 180
What is a right angle?
An angle that is exactly 90
Area of sector
Angle of sector / 360 x Area of circle
Length of arc
Angle of sector / 360 x Circumference of circle
Alternate angles (Z angles)
Are the same
Corresponding angles (F angles)
Are the same
Surface area of solid
Area of net
Area of parallelogram
B x H
Volume of prism
Cross sectional area x length
The formula triangle for distance speed and time would be?
D S x T
Time
D / S
Speed
D / T
Mass
D x V
Volume of cuboid
L x W x H
The formula triangle for mass density and volume would be?
M D x V
Density
M / V
Isosceles triangle
Two sides are the same. Two angles are the same.
Volume of frustum
V of origional cone - V of removed cone
The sine rule
a / sinA = b / sinB = c / sinC
Pythagoras' theorem
a2 + b2 = h2
The cosine rule
a2 = b2 + c2 - 2bc COS A or COS A = b2+c2-a2 / 2bc
Exterior angle of a triangle
equals sum of opposite interior angles
In factorising quadratic equations a minus then a plus makes a?
minus then a minus
In factorising quadratic equations a minus and a minus makes a?
plus then a minus
In factorising quadratic equations a plus then a minus makes a?
plus then a minus
In factorising quadratic equations a plus then a plus makes a?
plus then a plus
What formula is used to determine where an x point meets a y point on a particular line?
y=mx+c
Circumference of circle
π x D
Area of circle
π x r2
Volume
M / D
Probability-the AND rule
P of A and B happening is (P of A) times (P of B)
Probability-the OR rule
P of A or B happening is (P of A) add (P of B)
Graphs: How would you decide wich place to put the gradient numbers?
Rise / Run
Distance
S x T
What is the mnemonic word to decide which formula triangle to use trigonometry?
SOKATOA! 'soh cah toa'
What are the formula triangles known as 'soh cah toa'?
Sin Opposite Hypotenuse, Cos Adjacent Hypotenuse, Tan Opposite Adjacent
When one straight line crosses two parallel lines
The two bunches of angles are the same
