G S Rehill's Interactive Maths Software Series - "Building a Strong Foundation in Mathematics" from mathsteacher.com.au.

Order a 12-month Year 7 Interactive Maths software Homework Licence for only $19.95. Order a 12-month Year 8 Interactive Maths software Homework Licence for only $19.95. Order a 12-month Year 9 Interactive Maths software Homework Licence for only $19.95. Order a 12-month Year 10 Interactive Maths software Homework Licence for only $19.95.

Year 7 Interactive Maths - Second Edition


Parallel Lines

If two lines are in the same plane and do not intersect, then the lines are said to be parallel.

The lines AB and CD are parallel


Note:

Arrows are placed on the lines AB and CD to indicate that they are parallel.


A line that meets two or more parallel lines is called a transversal.  Line PQRS in the following diagram is a transversal.

PQRS is called the transversal

 

If two parallel lines are cut by a transversal as shown in the next diagram, we refer as follows to the angles formed:

  • z and x (or u and v) are alternate angles
  • x and y are corresponding angles
  • u and x (or z and v) are allied (or co-interior) angles
  • y and z are vertically opposite angles
Remember that:
  • Alternate angles are always equal.
  • Corresponding angles are always equal.
  • Allied (or co-interior) angles are supplementary.
  • Vertically opposite angles are always equal.


Example 9

Use the information given in the diagram to find:

a.  x
b.  y
c.  z
d.  u
e.  p

Solution:

x = 130     {Alternate angles}

y = 26     {Vertically opposite angles}

z = 50     {Allied angles}

u = 50     {Alternate angles}

p = 25     {Corresponding angles}


Key Terms

parallel lines, transversal, alternate angles, corresponding angles, allied angles, co-interior angles, vertically opposite angles


| Home Page | Order Maths Software | About the Series | Maths Software Tutorials |
| Year 7 Maths Software | Year 8 Maths Software | Year 9 Maths Software | Year 10 Maths Software |
| Homework Software | Tutor Software | Maths Software Platform | Trial Maths Software |
| Feedback | About mathsteacher.com.au | Terms and Conditions | Our Policies | Links | Contact |

Copyright 2000-2019 mathsteacher.com Pty Ltd.  All rights reserved.
Australian Business Number 53 056 217 611

Copyright instructions for educational institutions

Please read the Terms and Conditions of Use of this Website and our Privacy and Other Policies.
If you experience difficulties when using this Website, tell us through the feedback form or by phoning the contact telephone number.