Chapter 3: Measurement and Pythagoras’ theorem (Part 1)

Saumil S. Sharma B.Sc., MBA

NSW Syllabus for the Australian CurriculumCambridge MATHS for Year 8

Identification of Shapes

Units of Length• For thousands of years, civilisations have found ways to

measure length. The Egyptians, for example, used the cubit (length of an arm from the elbow to the tip of the middle fi nger), the Romans used the pace (5 feet) and the English developed their imperial system using inches, feet, yards and miles. The modern-day system used in Australia (and most other countries) is the metric system, which was developed in France in the 1790s and is based on the unit called the metre.

• We use units of length to describe the distance between two points, or the distance around the outside of a shape, called the perimeter.

Inter conversion of metric units

“Kilo” means thousand times. For example kilogram is equal to 1000 grams.“Centi” means one hundredth part. Therefore, centi meter is a hundredth part of a metre.“Milli” means one thousandth part. E.g. milligram is a thousandth part of a gram.• To convert Kilometer into metre multiply by 1000 and metre into kilometre divide by

1000• To convert metre into centimetre multiply by 100 and centimetre into metre divide by

100• To convert centimetre into millimetre multiply by 10 and millimetre into centimetre

divide by 10

Example

Perimeter

• “Peri” means outer and “meter” means to measure. Therefore, the distance around the outside of a shape, called the perimeter.

Discussion

Example

Example