W9.4

Front

W9.4

Calculate the perimeter of this shape:

Back

Hint:

To calculate the perimeter you need to add up all the lengths.

First you need to work out the missing lengths. Use what we know from the other horizontal lenghts to work out the missing horizontal length, and the vertical ones for the missing vertical length.

Front

Well done!

The missing lengths are :

horizontal: 7 - 4 = 3 cm

vertical 2 + 3 = 5 cm

now we can add up:

2 + 4 + 3 + 7 + 3 + 5 = 24 cm

Now, work out the area.

hint: to work out the area, break down the shape in two rectangles, and multiply the lenght x width.

Back

I am going to cut my shape vertically in two rectangles.

on the left hand side I have:

5 x 3 = 15 cm2

on the right hand side I have:

4 x 3 = 12 cm2

total area: 15 + 12 = 27 cm2

You could also have cut your shape horizontally and the overall total should be the same.