Entry Task

Learning Target: I can…..

… work with the relationship between the dimensions of and the circumference and area of circles. (Sec. 10.6/10.7)… work with the relationship between the dimensions of and the arc length and area of partial circles. (Sec. 10.6/10.7)

Practicing

𝐴=𝜋 𝑟 2

𝐴=𝜋 (21)2

𝐴=441𝜋𝑜𝑟 1384.74 𝑓𝑡 2

Because the Diameter is 42’ the radius is half of that or 21’

Segments and Sectors

• We will also find areas of segments and sectors which are parts of circles. They are shown below.

With your neighbors …..

• Your task today as a group is to find the area of the shaded regions of the following sector and segment. Once you have these answers, check in with Mr. S. and then begin the homework or attempt the challenge problem.

Your challenge today is to find the area of the following segments. Solve these and show/explain how you got your

answers to Mr. S and earn 5 extra credit points on your homework for assignment 141.

• 1) Find the area of the shaded segment as a percent of the total area of the circle. Round your answer to the nearest percent.

• 2) Use the figure to the right to find a formula for the area of the shaded segment in terms of r, sin x, and cos x.