before we start, recall :

7
Before we start, recall: Complete the “mental math” chart below: C= 2 r Radius Diameter Circumferenc e Area 5 inches 14 ft. 22 m. 100 m 2 C= D

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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 Presentation

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Page 1: Before we start,  recall :

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

Page 2: Before we start,  recall :

Arc LengthDuring today’s lesson you will solve problems involving arc

length.

Page 3: Before we start,  recall :

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

Page 4: Before we start,  recall :

Formula: Arc Length

Arc Length is a fractional part of circumference.

A. L. = Arc◌ / 360 x 2Пr22ПD22

Page 5: Before we start,  recall :

Example: Arc LengthIf the radius is 24 cm and m < BTA = 60, then what is the length of AB?

60◌

Page 6: Before we start,  recall :

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).

Page 7: Before we start,  recall :

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.