Everything Maths Grade 10

DID YOU KNOW?

The acre and the hectare are two common measurements used for the area of land. One hectare is about 0,01

square kilometres and one acre is about 0,004 square kilometres.

VISIT:

The video below shows some examples of calculations involving the area of a circle.

See video:2GRNatwww.everythingmaths.co.za

Worked example 1: Finding the area of a polygon

QUESTION

Find the area of the following parallelogram:

A

B C

E D

5 mm

3 mm 4 mm

SOLUTION

Step 1: Find the heightBE

AB^2 =BE^2 +AE^2 Pythagoras

)BE^2 =AB^2 AE^2

= 5^2  32

= 16

)BE=4 mm

Step 2: Find the area using the formula for a parallelogram

area=bh

=ADBE

= 7 4

=28 mm^2

VISIT:

The following Phet simulation allows you to build different shapes and calculate the area and perimeter for the

shapes:Phet: area builder.

Chapter 13. Measurements 417