Overview and Background

This activity will satisfy the following Common Core State Standard:

CCSS.MATH.CONTENT.HSG.C.B.5

Lesson Plan and Activity

Begin this activity by reviewing that arc length is the distance around a circle between two points (a portion of the circumference), and the formula to find arc length is
S= 2πr( θ / 360 ), S being arc length, r is the radius, and θ is the angle in degrees.

Next, have students work in groups of 2 or 3 to create 3 different scenarios where the angle measure is different. Students will place the clip P anywhere on the circle and measure the angles (between the horse and point P) each time with a protractor. The radius will be measured with a ruler. Students will use the formula to calculate the arc length.

After students have completed all three scenarios, they will check their results by measuring the arc length with a string.

Materials Needed

Print these objects before class. You need one set per group, along with string.

Skills Learned

arc length

Duration of Lesson

25 minutes

Arc Length- Horse Problem