Perimeter, area and volume
Where a and b are the lengths of the parallel sides
and h is their perpendicular separation:
Area of a trapezium =
1
2
(a + b) h
Volume of a prism = area of cross section × length
Where r is the radius and d is the diameter:
Circumference of a circle = 2πr = πd
Area of a circle = πr 2
Quadratic formula
The solution of ax2 + bx + c = 0
where a ≠ 0
x = – – b b ac
a
± 2 4
2
Pythagoras’ Theorem and Trigonometry
In any right-angled triangle where a, b and c are
the length of the sides and c is the hypotenuse:
a2 + b2 = c2
In any right-angled triangle ABC where a, b and c
are the length of the sides and c is the
hypotenuse:
sin A =
a
c cos A =
b
c tan A =
a
b
In any triangle ABC where a, b and c are the
length of the sides:
sine rule: = =
abc
sin sin sin ABC
cosine rule: a2 = b2 + c2 – 2bc cos A
Area of triangle =
1
2
ab sin C
Compound Interest
Where P is the principal amount, r is the interest
rate over a given period and n is number of times
that the interest is compounded:
Total accrued = P +
n r 1
100
Probability
Where P (A) is the probability of outcome A and
P (B) is the probability of outcome B:
P(A or B) = P(A) + P(B) – P(A and B)
P(A and B) = P(A given B) P(B