Area of a Circle and Golf Ball Bridge Design

Announcements:

• This week in Science: Plants for Food and Fibre
• This week in Math: Transformations
• Field Trip to Drumheller will be June 24th - Paperwork will be sent home later this week

Math:

We finished the Circles and Area Unit with a hands-on activity that helped students better understand the Area of a Circle equation.

We divided the circle into eighths and then divided one sector into sixteenths.

We then assembled the sectors into a rectangle.

The width or base of the rectangle is the same as the radius (r) of the original circle. The length or height is equal to 1/2 of the circumference (C).

Area of a rectangle is length x width. If we substitute in r and 1/2C ... A = 1/2C x r

For most students this was far enough to take the activity, but a few wanted to understand how the area of a circle equation was related to the area of the rectangle.

We reviewed the two circumference equations: C = Pi x diameter AND C = 2 x Pi x radius

We then substituted the C = 2 x Pi x r equation into the area of a rectangle equation replacing C with 2 x Pi x r

A = 1/2 (2 x Pi x r) r

After reducing we were left with:

Science:

We completed the Structures and Forces Unit with a Golf Ball Bridge Challenge. Students did a great job designing, building, testing, and reflecting on their projects. There were many unique and successful designs!