ANGLESANGLES

Dr Duxbury – Titus Salt School

TYPES OF ANGLESTYPES OF ANGLES

How many types of angles can you think of?

ACUTEOBTUSE

REFLEXRIGHT-ANGLE

ACUTE ANGLESACUTE ANGLES

An acute angle is bigger than 0° and less than 90°

OBTUSE ANGLESOBTUSE ANGLES

An obtuse angle is bigger than 90° but smaller than 180°

REFLEX ANGLESREFLEX ANGLES

A reflex angle is bigger than 180° and less than 360º

RIGHT-ANGLESRIGHT-ANGLES

A right-angle is always 90º

MEASURING ACUTE ANGLESMEASURING ACUTE ANGLES

MEASURING ACUTE ANGLESMEASURING ACUTE ANGLES

MEASURING ACUTE ANGLESMEASURING ACUTE ANGLES

MEASURING ACUTE ANGLESMEASURING ACUTE ANGLES

80º

MEASURING OBTUSE ANGLESMEASURING OBTUSE ANGLES

MEASURING OBTUSE ANGLESMEASURING OBTUSE ANGLES

145º

MEASURING REFLEX ANGLESMEASURING REFLEX ANGLES

360º

130º

Angle = 360º - 130º = 230º

DRAWING ANGLESDRAWING ANGLES

E.g. Draw the angle 56º

Use a SHARP pencil!

Draw the angle 56º

DRAWING ANGLESDRAWING ANGLES

56 º56 º

Always label Always label your angleyour angle

DRAWING ANGLESDRAWING ANGLESDraw the angle 56º

DRAWING REFLEX ANGLESDRAWING REFLEX ANGLESDraw the angle 200º

180º

20º

DRAWING REFLEX ANGLESDRAWING REFLEX ANGLESDraw the angle 200º

200º

EXERCISEEXERCISE

1.) Draw a triangle in your book and measure all the angles.

What do they all add up to?

2.) Draw any four sided shape? Again what do the angles all add up to?

3.) As accurately as you can, draw the following angles:

45º 130º 184º 210º 308º

(Get your neighbour to check them for you)