Shapes And Angles

What cute little angles!

What’s so right about these?

They just look like square corners to me!

360 degrees4 right angles

4 lots of 90 degrees

2 lots of 180 degreesHow many ways do I have to say it?

Everyone knows this is

180 degrees!

Using a Protractor

Measuring, calculating and drawing angles...

learning objectives

To use a protractor to:a) measure acute and obtuse

angles to the nearest degree.b) draw acute and obtuse angles

to the nearest degree.To calculate angles on a straight

line.

What do we use to help us while measuring angles?

A protractor

Here is a standard protractor

When we use a protractor, we need to line it up

correctly.

You need to make sure the protractor is lined up correctly.

Is this ready to measure the angle?

Were you right?......................it wasn’t

Look for the upside down ‘T’ in the middle of the straight line on your protractor.

This needs to be exactly on the vertex of your angle.

We need to remember.....

It doesn’t matter which way round the angle is, you ALWAYS need to line the upsidedown ‘T’ to the vertexof the angle.

Now you are ready.

Read from the 0°, and follow the inner set of numbers.

What does it measure?

This angle measures 35°.

Challenge!

Investigating Right AnglesSort the quadrilaterals into a table like this.

0 right angles 1 right angle 2 right angles 3 right angles 4 right angles

AB

C

D

F

E

G

H