**Driving Question:** Are all triangles the same?

**Learning Target: **To be able to use angles to solve puzzles.

**Success Criteria**

*Beginning*

*Measure and draw angles accurately; distinguish between acute, obtuse and reflex angles.*

*Developing*

*Apply the angle properties of angles at a point, on a straight line and vertically opposite angles.*

*Mastering*

*Investigating the angles in polygons. *

**Resources**

**Beginning**

B1
What is an angle? How do we measure an angle? What does this tell us?

**Developing**

D1
__Angles around a point - Trail __(print)

D2
Use whiteboard to test understanding.

**Mastering**

M1

To investigate the angle in a triangle.
What can we say about the angles in an equilateral triangle?

*Ask students to cut out a triangle and then mark the three corners.*

*Now cut the corners off the triangle corners.*

*Now put the points together to find out what the angles in a triangle add up to. *

M2

M4

To investigate and then remember the rules for calculating internal angles in polygons.

In words, can you state the rule for the internal angles of any polygon?

*Ask students to draw a six-sided shape (but making sure it is not a concave shape - see the picture). *

*Now pick one corner and draw straight lines from this corner to each of the other corners. *

*What shapes does this form within the larger shape?*

*What does this tell us about angles in the larger shape?*

*Ask students to now investigate other polygons.*
*Draw an example of each shape (they do not need to cut them out) and follow the method above. *
*Ask students to make a poster showing their findings. *
*Use the internet to find the names of the different polygons. *

*Use this information to complete the table below.*