Formulas

Question 1

Area of any triangle

Answer 1

1/2 x a x b x SinC

Question 2

Pythagoras’ theorem

Answer 2

c² = a² + b²

Question 3

Sine rule (side)

Answer 3

a b
——— = ———
SinA SinB

Question 4

Sine rule (angle)

Answer 4

SinA SinB
——— = ———
a b

Question 5

Cosine rule (side)

Answer 5

a² = b² + c² - 2bcCosA

Question 6

Cosine rule (angle)

Answer 6

CosA = b² + c² - a²
———————
2bc

Question 7

Area of sector

Answer 7

Angle
———— x πr²
360

Question 8

Arc length

Answer 8

Angle
——— x πd
360

Question 9

Trigonometry

Answer 9

SOH CAH TOA

Question 10

Volume of prism

Answer 10

Area of cross section x length

Question 11

Volume of pyramid

Answer 11

1/3 x area base x height

Question 12

Volume of sphere

Answer 12

4/3 πr³

Question 13

Surface area of sphere

Answer 13

4πr²

Question 14

Volume of cone

Answer 14

1/3 π r² h

Question 15

Surface area of cone

Answer 15

π r² + π (slant height)

Question 16

Quadratic formula

Answer 16

X = -b ±√b² - 4ac
———————
2a

Question 17

Polygons: interior angle

Answer 17

(N-2) x 180
——————
N

Question 18

Polygons: exterior angle

Answer 18

360 ÷ n

Question 19

Polygons: no. of sides

Answer 19

360 ÷ exterior angle

Question 20

Speed

Answer 20

Distance
—————
Time

Question 21

Density

Answer 21

Mass
—————
Volume

Question 22

Direct proportion

Answer 22

X = ky

Question 23

Inverse proportion

Answer 23

X = k
——
y