Knowing angle properties

Knowing angle properties

Pencil and paperOnline interactive
Overview
Using this Resource
Connecting to the Curriculum
Marking Student Responses
Further Resources
This task is about angle properties.
A sculpture has been made with a triangular base and a straight top piece.
The angles in the triangle are all different and the top piece is parallel with the base of the triangle.
 
knowing-angle-properties-diagram.png

Question

a) Which angle is the same as angle b? (Select one)

    • a

    • x 

    • c 

    • y

Question

b)  Which angle is the same as angle c? (Select one)

    • a 

    • b

    • x

    • y

c) How did you work out questions a) and b)?

Question

d) What do angles a + b + c add up to? (Select one)

    • 90º

    • 180º 

    • 270º 

    • 360º

e) How did you work out question d)?
Task administration: 
This task can be completed with pencil and paper or online (with some auto-marking displayed to students).
Level:
5
Curriculum info: 
Maths, Geometry and Measurement, Shape
Keywords: 
angles, parallel lines, triangles, angle properties, alternate angles
Description of task: 
Students use their knowledge of angle properties of parallel lines and angles on a straight line to identify similar angles and to calculate the sum of three angles giving appropriate explanations.
Learning Progression Frameworks
This resource can provide evidence of learning associated with
Geometric thinking, set 6
within the Mathematics Learning Progressions Frameworks.
Read more about the Learning Progressions Frameworks.
Answers/responses: 

 

Y11 (05/2000)

a)

x

very easy

b)

y

very easy

c)

Alternate angles (are equal on parallel lines).
[Accept other correct explanations that use at least two of: co-interior, corresponding or vertically opposite angles.]

difficult

d)

180º

very easy

e)

Either:

•   Angles on a straight line (sum to 180°).
•   Angles in a triangle (sum to 180°).

easy

NOTE: This item can be used as a proof for the angles in a triangle summing to 180°.