before we start, recall :
DESCRIPTION
Before we start, recall : . Complete the “mental math” chart below:. C= ∏D . C= 2∏r . Arc Length. During today’s lesson you will solve problems involving arc length. Definition: Arc Length. length of an arc ( arc length ) . - PowerPoint PPT PresentationTRANSCRIPT
Before we start, recall: Complete the “mental math” chart below:
C= 2∏r
Radius Diameter Circumference
Area
5 inches14 ft.
22 ∏ m.100 ∏ m2
C= ∏D
Arc LengthDuring today’s lesson you will solve problems involving arc
length.
Definition: Arc LengthThe _______________________is a fractional part of a circle’s circumference.
length of an arc (arc length)
45◦
Many people confuse arc length with
arc measure. They are not the same.
Note: Every arc has a measure of __. The lengths of the arcs are ________________. different
Formula: Arc Length
Arc Length is a fractional part of circumference.
A. L. = Arc◌ / 360 x 2Пr22ПD22
Example: Arc LengthIf the radius is 24 cm and m < BTA = 60, then what is the length of AB?
60◌
If the length of ROT is 116 П meters, what is the radius of the circle?
R
O
T
ALERT! Determine these two things before writing the formula: 1. Arc measure , and 2. circumference (2П r or П D).
HOMEWORKArc Length WS: Be sure to write the formula, then substitute necessary information before solving. Show ALL work on a separate sheet of paper to receive full credit.