test two on chapters 3, 4 and 5

• in convex polygons, all interior angles are less than 180 degrees.

  
• All regular polygons are convex. Like a pentagon or something.
• In a concave polygon, some interior angles are more than 180 degrees .
• Is this a concave shape?

  Yes.

  
• What is the formula for the sum of interior angles?

  (n-2)x 180
• What is the sum of a pentagon's interior angles?

  540
• What is the sum of a hexagon's interior angles?

  720
• What is the sum of a heptagon's interior angles?

  900
• What is the sum of an octagon's interior angles?

  1080
• What is the sum of a nonagon's interior angles?

  1260
• What is the sum of a decagon's interior angles?

  1440
• The sum of exterior angles for any polygon is 360 degrees.
• Interior angles + Exterior angles = 180 degrees at each vertex

  
• straight line = 180
• around a point = 360
• 360 / num of sides = ext angle
• (n x 2) / num of sides = int angle
• num of sides = same of num of interior/exterior angles
• tessellation = shapes that fit together with no gap
• shapes that tessellate are = squares, hexagons, kites and triangles.
• What should a line of best fit look like?

  1. Pass through the centre of the data
  2. Same number of points above and below
  3. Not be extended past the data either end
• A two way table shows you two or more variables at the same time.
• formula for finding mean from a table:

  frequency x variable / total frequency
• formula for estimate of the mean from grouped data : total of frequency x midpoint of variable / total frequency
• cumulative frequency is a running total
• work out each value of cumulative frequency.

  A) 1

  B) 4

  C) 9

  D) 11

  E) 12

  
• Guide for drawing a cumulative frequency graph:

  1. cumulative frequency goes on the y axis ONLY
  2. plot the higher bound of the ground on the graph
  3. It should always be a smooth S shape.

  
• IQR = Upper Quartile- Lower Quartile
• LQ = 1/4 of the highest value on the y axis.
• Median = 1/2 of the highest value
• UQ = 3/4 of the highest value
• IQR = Interquartile Range
• LQ = Lower Quartile
• UQ = Upper Quartile
• what are these?

  A) largest value

  B) smallest value

  C) upper quartile

  
• step graphs look like:

  
• Speed = Distance / Time
• what are these?

  A) distance

  B) speed

  C) time

  
• distance/time graphs look like

  
• The formula for Exponential Graphs is y=axb²