What this quiz covers

Grade 9 Drawing & Interpreting Graphs Quiz draws its questions at random from 22 questions across these topics:


Worked examples

A few of the question types, with full solutions, so you know what to expect.

Pie charts. A survey of 60 learners is shown on a pie chart. 18 chose soccer. What angle represents soccer?

  1. 108°
  2. 120°
  3. 96°
  4. 60°

Answer: 108°

Angle = (frequency ÷ total) × 360°

= (18 ÷ 60) × 360° = 0,3 × 360°

Pie charts. The pie chart below shows how 200 learners travel to school. How many learners travel by car?

  1. 30
  2. 40
  3. 50
  4. 80

Answer: 40

Read the car slice from the chart: 72°.

Frequency = (angle ÷ 360°) × total

= (72 ÷ 360) × 200 = 0,2 × 200

Pie charts. Using the same pie chart of 200 learners, what percentage walk to school?

  1. 40%
  2. 36%
  3. 25%
  4. 144%

Answer: 40%

The walking slice is 144°.

Percentage = (144 ÷ 360) × 100%

Tip: A 144° slice is NOT 144%. Always divide by 360 first.

Pie charts. On a pie chart, the angles calculated are 108°, 90°, 72°, 54° and 36°. What must you check before drawing?

  1. That they add up to 360°
  2. That they add up to 100°
  3. That the largest is first
  4. That there are exactly five

Answer: That they add up to 360°

A full circle is 360°, so every slice together must account for exactly 360°.

108 + 90 + 72 + 54 + 36 = 360 (correct)

Pie charts. 80 people were surveyed and 24 chose option A. What angle represents option A on a pie chart?

  1. 96°
  2. 108°
  3. 120°
  4. 72°

Answer: 108°

(24 ÷ 80) × 360° = 0,3 × 360°