Areas and volumes with a cost or a time at the end, Pythagoras and trigonometry in two steps, polygons, similar solids, sectors and the sine and cosine rules.
What you will learn
- Break a shape into parts you can find
- Use one result to find the next (a side, then an angle)
- Use length, area and volume scale factors
- Give an answer in the units and accuracy asked
One result feeds the next
Many geometry problems are two smaller questions joined together.
Label what each step finds.
- right angle at B, AB = 6 cm, BC = 8 cm: AC² = 6² + 8² = 100, so AC = 10 cm
- in triangle ACD, angle CAD = 35° and the right angle is at C
- CD is opposite 35° and AC is adjacent: CD = 10 × tan 35° = 7.00 cm
Keep the unrounded AC on your calculator for the second step.
The rest of this lesson and its 11 practice questions are locked.
In this lesson
- One result feeds the next
- Volume, then a rate
- Scale factors
11 practice questions, marked as you go; about 30 minutes in all.
In this unit: Exam problems
The long problems that end a paper, worth 4 to 6 marks: number, algebra, ratio, geometry and statistics, Foundation and Higher, with and without a calculator, marked step by step.