Number, Algebra and Geometry

Question 1

quadratic sequences finding the nth term:

Answer 1

if the second difference is 2 then it is nsquared
if the second difference is 4 then it is 2nsquared
if the second difference is 6 then it is 3nsquared

Question 2

Polygons:

Sum of interior angles

Answer 2

(n-2) x 180
n is the number of sides
works for irregular and regular polygons

Question 3

Polygons:

Exterior angle

Answer 3

= 360/n
so sum of exterior angles = 360
n is the number of sides

Question 4

Polygons

Interior angle

Answer 4

180 - exterior angle

Question 5

are of a parallelogram

Answer 5

A = b x (vertical) h

Question 6

area of a triangle

Answer 6

A = 1/2 x b x h (vertically)

Question 7

Metric units

Answer 7

1cm = 10mm
1m = 100cm
1km = 1000km
1kg = 1000g
1 tonne = 1000kg
1l = 1000 ml
1 cm cubed = 1ml

Question 8

Metric - imperial conversion

Answer 8

1 kg = 2.2 lbs
1 l = 1 3/4 pints
1 inch = 2.5 cm
1 gallon = 4.5 litres
1 foot = 30 cm
1 mile = 1.6 km ( 5 miles = 8 km)

Question 9

Z shape

Answer 9

alternate angles

the angles are the same

Question 10

c shape

Answer 10

Supplementary angles

add up to 180

Question 11

F shape

Answer 11

corresponding angles

the angles are the same

Question 12

exterior angle of a triangle

Answer 12

= sum of the opposite angles in the triangle

Question 13

equation for frequency density

Answer 13

frequency/width

used in histograms

Question 14

finding the mean from grouped requency tables

Answer 14

sum of the frequency x midpoint / sum of the frequencys

Question 15

steps for making x the subject of the formula

Answer 15

• get rid of the square root signs by squaring both sides
• get evrything off the bottom by multiplying every term in the equation
• multiply out brackets
• collect all subject terms on one side eg. anything with x on one side anything without on the other
• reduce it to the from Ax + b
  a and b are just letters not including x
• divide by A to give x = b/a