Term 2 Week 7

The volume of Jupiter is more than that of all the other planets combined, but still only a small fraction of the volume of the sun.

This week we start the topic: Perimeter, Area and Volume. Students will already know how to work out the perimeter and volume of many shapes. This year we will extend that knowledge so students will be able to be able to add shapes or volumes together to make more complex shapes or volumes.

We will revisit Pythagoras so that lengths of right angle triangles can be computed. We will also do some calculations with circles and parts of circles (like pizza slices)

An example problem would be to work out the perimeter of a 20cm radius pizza slice - like you were an adventurous ant doing a walk around the edge of one. The pizza is divided equally into six parts.

To answer the question we need to add up the lines around the edge of the slice - there are two straight lines and a curved line. The straight ones are easy - they are just the radius of the circle - 2 x 20cm, but the round part is a little harder. We can find it by finding a fraction of the whole circle. - in this case 1/6th of a circle. So we multiply the circumference of the whole circle (Pi x diameter) by the fraction of a circle (1/6) . This gives us 3.14 x 40cm x 1/6 = 125.6/6 cm = ~ 31 cm. So the total edge of the slice is: 2 x 20 cm + 31 cm = 71 cm.

The Perimeter, Area and Volume assignment is here

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