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| # recognize and apply “corresponding sides of similar triangles are proportional”. | | # recognize and apply “corresponding sides of similar triangles are proportional”. |
| ===Notes for teachers=== | | ===Notes for teachers=== |
| + | # The teacher can bring different sized photographs got from same negative like stamp size, passport size and a post card size . |
| + | # Compare them and say that all photos are look alikes and are proportionate. only the size differs. |
| + | # She can also mention about scale concept in graphical representation. |
| + | # Hence similar triangles are the same proportionate triangles but of different sizes. |
| + | # Two triangles are similar if they have: |
| + | * all their angles equal |
| + | * corresponding sides in the same ratio |
| + | # In similar triangles, the sides facing the equal angles are always in the same ratio. Application of this finds its use in finding the unknown lengths in similar triangles . For this :<br> |
| + | Step 1: Find the ratio of corresponding sides in pairs of similar triangles.<br> |
| + | Step 2: Use that ratio to find the unknown lengths.<br> |
| ===Activity No # 1. SIMILAR TRIANGLES=== | | ===Activity No # 1. SIMILAR TRIANGLES=== |
| {| style="height:10px; float:right; align:center;" | | {| style="height:10px; float:right; align:center;" |
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| # They should know how to find ratio. | | # They should know how to find ratio. |
| # They should know to find area and perimeter of triangles. | | # They should know to find area and perimeter of triangles. |
− | # The students should have clarity between the terms congruent and similar.
| |
| *Multimedia resources: Laptop | | *Multimedia resources: Laptop |
| *Website interactives/ links/ / Geogebra Applets | | *Website interactives/ links/ / Geogebra Applets |
| *Process: | | *Process: |
− | # The teacher can bring different sized photographs got from same negative like stamp size, passport size and a post card size . Compare them and say that all photos are look alikes and are proportionate . only the size differs.
| + | |
− | # She can also mention about scale concept in graphical representation.
| + | |
− | # Hence similar triangles are the same proportionate triangles but of different sizes.
| |
− | # Two triangles are similar if they have:
| |
− | * all their angles equal
| |
− | * corresponding sides in the same ratio
| |
− | # In similar triangles, the sides facing the equal angles are always in the same ratio.
| |
− | # Application of this finds its use in finding the unknown lengths in similar triangles . For this :
| |
− | Step 1: Find the ratio of corresponding sides in pairs of similar triangles.
| |
− | Step 2: Use that ratio to find the unknown lengths.
| |
| *Developmental Questions: | | *Developmental Questions: |
| # Look at the shape of both triangles being formed? (look alikes ) | | # Look at the shape of both triangles being formed? (look alikes ) |