Arc Length
Lesson Prep
Lesson Details
Duration: 50 minutes
Learning Goal: Give students an opportunity to figure out how to calculate the length of an arc on their own before moving into formal notes and practice.
Prework
Consider joining our free online workshop to explore 3 Act Math more in depth
If possible, use big whiteboards and have each group member write with different colors
Write pre-scripted questions for audience members to ask during presentations
Classwork
3 Act Math - Nardo Ring
Standards
Common Core
HSG.C.B.5 – Derive using similarity the fact that the length of the arc intercepted by an angle is proportional to the radius, and define the radian measure of the angle as the constant of proportionality; derive the formula for the area of a sector.
TEKS
G.12(B) – apply the proportional relationship between the measure of an arc length of a circle and the circumference of the circle to solve problems
G.12(D) – describe radian measure of an angle as the ratio of the length of an arc intercepted by a central angle and the radius of the circle