This week we extended our unit on Proportionality to cover Similar Figures. On Tuesday/Wednesday we made a 3 page Mini Book covering all the various parts of Similar Figures. We also learned that NEW word that I’ve been teasing about…. SCALE FACTOR!
The outside of our book contained our title as well as our “I Can” statement of what we would be able to do once we had mastered the knowledge behind Similar Figures.
When you open up the first flap, we began to discuss the definition of similar figures. We then drew examples and came up with the characteristics of similar figures showed us that both shapes can be similar if they are of different dimensions.
To explore that further we went on to create two models of similar figures that we were able to count and test the difference. Then we added in that to be similar BOTH DIMENSIONS must change!
But how do we know that we are right? We can check it using Ratios! So we created our ratios of our two new quadrilaterals and compared them using cross products. Okay, we have that down pat! Now let’s bring in that new word, SCALE FACTOR! Yep, makes life so much easier if we are able to multiply our denominators and numerators by a number (the scale factor) to determine equivalent ratios!
Next up, it was time to try it out! Each group got a baggie of centimeter cubes and went to town creating some amazing models! Check them out below!
As a wrap-up, they answered a Post It, Prove It for me that asked, “Create two similar figures and prove their similarity through a proportion. Check your work by comparing the ratios in the proportion using cross products or similar figures.”
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