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| + | === 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 [[:File:Angle sum property of triangle.ggb|open]] the file |
| + | |
| + | === Process (How to do the activity) === |
| + | {{Geogebra|xbwbcdgn}} |
| + | * 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 - [https://karnatakaeducation.org.in/KOER/en/index.php/Triangles?veaction=edit§ion=20 click here] |
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| + | [[Category:Triangles]] |