Difference between revisions of "Angle sum property of a Triangle"
Jump to navigation
Jump to search
m (added Category:Triangles using HotCat) |
|||
| Line 1: | Line 1: | ||
=== Objectives === | === Objectives === | ||
| + | * To establish the angle sum property of a triangle | ||
| + | * To help visualization of the geometric proof | ||
=== Estimated Time === | === Estimated Time === | ||
| + | 30 minutes | ||
=== Prerequisites/Instructions, prior preparations, if any === | === Prerequisites/Instructions, prior preparations, if any === | ||
| + | Prior understanding of point, lines and angles, adjacent angles, vertically opposite angles, linear pair, parallel lines, alternate angles, corresponding angles. | ||
=== Materials/ Resources needed === | === Materials/ Resources needed === | ||
| Line 15: | Line 19: | ||
** What can you say about the line drawn? | ** What can you say about the line drawn? | ||
** Is it parallel to one of the sides? | ** Is it parallel to one of the sides? | ||
| − | ** What can you say about the pairs of angles – look at the matching | + | ** What can you say about the pairs of angles – look at the matching colours. |
** Once the parallel line reaches the vertex, how many angles are formed? | ** Once the parallel line reaches the vertex, how many angles are formed? | ||
** Students should be able to identify the two angles moving are corresponding angles as the line moving is parallel to one of the sides. | ** Students should be able to identify the two angles moving are corresponding angles as the line moving is parallel to one of the sides. | ||
Latest revision as of 19:46, 19 December 2020
Objectives
- To establish the angle sum property of a triangle
- To help visualization of the geometric proof
Estimated Time
30 minutes
Prerequisites/Instructions, prior preparations, if any
Prior understanding of point, lines and angles, adjacent angles, vertically opposite angles, linear pair, parallel lines, alternate angles, corresponding angles.
Materials/ Resources needed
Click here to open the file
Process (How to do the activity)
Download this geogebra file from this link.
- Students should be able to recognize the corresponding angles formed when the parallel line is drawn.
- Students should be able to recognize the alternate angles formed. Is the alternate angle same as one of the angles of the triangle.
- Ask students what happens when the three angles of the triangle are placed adjacent to each other.
- What can you say about the line drawn?
- Is it parallel to one of the sides?
- What can you say about the pairs of angles – look at the matching colours.
- Once the parallel line reaches the vertex, how many angles are formed?
- Students should be able to identify the two angles moving are corresponding angles as the line moving is parallel to one of the sides.
- Students can see that when the three angles of the triangle are placed adjacent to each other they form a straight line.
Evaluation at the end of the activity
- In a triangle, if the sum of two angles is 60°, then what will be the measure of third angle?
- If a triangle has all three angles are equal in measure, then what will the measure of each angle?
Go back to the page - click here