Lines and angles Lesson objective:
To be able:
to draw lines and angles
to estimate the size of angles
to identify types of angle. [Level 4/5] Key words:
parallel
perpendicular
right
acute
obtuse Starter:
Sketch a pair of
parallel lines
Perpendicular lines

Slide 2:

Parallel lines – NEVER meet Random lines – Intersect at a point X Perpendicular lines – Intersect at right angles Draw the following lines and write down some names for them. X

Slide 3:

What is ANGLE ??? An angle is formed when two lines meet and is measured in degrees. We use a little circle ° following the number to mean degrees. For example 32° means 32 degrees. 32 °

Slide 4:

What is the size and the name of this angle? 90° - Right angle

Slide 5:

What is the size and the name of this angle? 180° - Half turn

Slide 6:

What is the size and the name of this angle? 360° - Full turn

Slide 7:

90° - Right angle 180° - Half turn 360° - Full turn IMPORTANT ANGLES TO REMEMBER

Slide 8:

What is the size and the name of this angle? Less than 90° - Acute angle

Slide 9:

All the angles which are less than 90° are ACUTE ANGLES

Slide 10:

What is the size and the name of this angle? Between 90° and 180°- Obtuse angle

Slide 11:

All the angles which are between 90° and 180° are OBTUSE ANGLES

Slide 12:

What is the size and the name of this angle? Between 180° and 360°- Reflex angle

Slide 13:

All the angles which are between 180° and 360° are REFLEX ANGLES

Slide 14:

Summary Acute Angle: less than 90°
Obtuse Angle: more than 90° but less than 180°
Reflex Angle: more than 180° but less than 360°

Slide 15:

AB = AC OR AB = CD and AD = BC AB is parallel to CD or AB//CD AD is parallel to BC or AD//BC EXAMPLE

Slide 16:

Write down which of the angles below are acute, which are obtuse and which are reflex. Estimate the size of each one. Work in pairs….

Slide 17:

a. BC = DE = CD b. BC = DE c. BC = CD Work in pairs…. d. BD = CE

Slide 18:

Identify any type of angles Obtuse angles Right
angles Work in pairs….

Slide 19:

Identify any type of angles Obtuse
angle Obtuse
angles Right
angles Acute
angles Work in pairs….

Slide 20:

http://mathspool2.co.uk/#/grade-c-2011/4544717033 PLENARY Easy angles => Type of angles

Slide 21:

The protractor helps us to measure the size of an angle. Later on we learn how to use it.

Slide 22:

http://www.mathplayground.com/alienangles.html
Estimate angles-NOT for this lesson

You do not have the permission to view this presentation. In order to view it, please
contact the author of the presentation.

Send to Blogs and Networks

Processing ....

Premium member

Use HTTPs

HTTPS (Hypertext Transfer Protocol Secure) is a protocol used by Web servers to transfer and display Web content securely. Most web browsers block content or generate a “mixed content” warning when users access web pages via HTTPS that contain embedded content loaded via HTTP. To prevent users from facing this, Use HTTPS option.