maths exam prep Flashcards
Rectangle area
length x width
Rectangle perimeter
2 x length + 2 x width
Triangle area
1/2 base x height
Triangle perimeter
add up all the sides
parallelogram area
Base x height
trapezium area
1/2 x height x sum of parallel sides
Circle area
πr²
Circle circumference
2πr
Distance
speed x time
Speed
distance/time
Time
distance/speed
Gradient of a graph
y/x
Mean
total of values/ sum of values
mode
Most frequent number
median
Middle value when numbers are arranged in order of size
Percent increase/decrease
(Actual change x 100)/ original
Total degrees in polygon
(Number of sides -2) x 180
Interior angle
Total degrees/number of sides
Number of sides
360/exterior angle
Sin angle =
opposite/hypotenuse
Cos angle
Adjacent/ hypotenuse
Tan angle
Opposite/adjacent
arc length
(Angle/360) x 2πr
Sector area
(angle/360) x πr²
Simple interest formula
I = PRT/100 I is interest P is principal amount R is rate of interest T is time
Compound interest formula
A= P = (1 + r/100)ⁿ P is amount invested r is the rate of interest n is number of years A is value of investment after n years
Venn diagram formula
n( A U B) = n(A) + n(B) - n(A n B)
Quadratic formula
x =( -b+-√b²-4ac) /(2a)
Equation of linear graph
y = mx + c M = gradient and c = y intercept
acceleration and deceleration =
Change in speed/time taken
distance travelled =
Area under speed time graph
volume of any prism =
Cross sectional area x length (or height)
Curved surface area of cylinder =
2πrh
Curved surface area of cone
πrl
curve surface area of sphere
4π²
Volume of pyramid
1/3 Ah
Volume of cylinder
πr²h
volume of cone
1/3πr²h
Volume of sphere
4/3πr³
