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| ===Objectives=== | | ===Objectives=== |
− | To understand what is a tangent and its relationship to the circle | + | To understand about the tangent and its relationship to the circle |
| ===Estimated Time=== | | ===Estimated Time=== |
| 30 minutes | | 30 minutes |
| | | |
| ===Prerequisites/Instructions, prior preparations, if any=== | | ===Prerequisites/Instructions, prior preparations, if any=== |
| + | Knowledge about Circle, radius, angle |
| + | |
| ===Materials/ Resources needed=== | | ===Materials/ Resources needed=== |
| + | Digital: Click here to [https://karnatakaeducation.org.in/KOER/en/images/2/2b/TANGENTS_TO_A_CIRCLE.ggb open] the file |
| + | |
| + | Non-digital:Paper, pencil, ruler, compass, protractor. |
| + | |
| ===Process (How to do the activity)=== | | ===Process (How to do the activity)=== |
| + | {{Geogebra|tk7wbpwe}} |
| + | |
| + | '''Procedure:''' |
| + | # 'A' is the center of the circle |
| + | # What are 'AD' and 'AE' with respect to the circle? |
| + | # What type of angles are ∠BDA and ∠BEA ? |
| + | # In any circle the radius drawn at the point of contact is perpendicular to the tangent. ∠BDA = ∠BEA = 90 |
| + | # We can draw two tangents to a circle from a point outside the circle |
| + | # Name the tangents drawn from the external point B to the circle |
| + | # Measure AD and AE. What is your conclusions? |
| + | # What type of triangles are BDA and BEA ? |
| + | # What is AB with respect to triangle BDA and BEA ? |
| + | # Are triangle BDA and BEA congruent to each other? |
| + | # The tangent drawn from an external point to a circle a] are equal b] subtend equal angle at the centre c] are equally inclined to the line joining the centre and external point. |
| + | # Properties of quadrilateral (sum of all angles) is 360 degrees |
| + | # Angle between the two tangents from a point outside the circle is supplementary to the angle subtended by the line segments joining points of contact at the centre. |
| + | |
| + | === Evaluation at the end of activity === |
| + | Tangents AP and AQ are drawn to circle with centre 'O', from an external point 'A'.Prove that ∠PAQ=2∠OPQ |
| | | |
| + | Go back - [https://karnatakaeducation.org.in/KOER/en/index.php/Circles?veaction=edit§ion=42 click here] |
| [[Category:Circles]] | | [[Category:Circles]] |