1. Unit 2: Ratios and Proportional Relationships
7th grade/6th grade accelerated math

2. 4.4 – Ratios and Pi

3. Exploring Circumference

4. Explore Activity
Use a measuring tape to find the circumference of 5 circular objects
Then, measure the distance across each item to find its diameter
Record each of the measurements of each object in the table below
Object
Circumference C
Diameter d
𝑪 𝒅

5. Determining Proportionality in Circles

6. Finding Missing Parts of a Circle
You know that 𝐶 𝑑 =𝜋 for all circles
You can use this ratio to find unknown measures
Ex: ”The circumference of circle A is approximately 94cm. The diameter of circle A is 30cm. The diameter of circle B is 15cm. What is the circumference of circle B?”