This optional lesson gives students an additional opportunity to practice finding unknown values in proportional relationships using contextual examples. The problems preview using the Pythagorean Theorem, which is a key idea in a subsequent lesson. They also preview finding all unknown values in right triangles, which is a key idea in a subsequent unit. Students have a chance to reason abstractly and quantitatively as they think about whether their answers make sense in context (MP2).
- Calculate unknown values in proportional relationships.
- Determine scale factors to describe similar figures (using words and other representations).
- Let’s find unknown values in proportional relationships.
- I can find scale factors and use them to solve problems.
One figure is similar to another if there is a sequence of rigid motions and dilations that takes the first figure onto the second.
Triangle \(A'B'C'\) is similar to triangle \(ABC\) because a rotation with center \(B\) followed by a dilation with center \(P\) takes \(ABC\) to \(A'B'C'\).