# Arcs of a circle

#### Everything You Need in One Place

Homework problems? Exam preparation? Trying to grasp a concept or just brushing up the basics? Our extensive help & practice library have got you covered.

#### Learn and Practice With Ease

Our proven video lessons ease you through problems quickly, and you get tonnes of friendly practice on questions that trip students up on tests and finals.

#### Instant and Unlimited Help

Our personalized learning platform enables you to instantly find the exact walkthrough to your specific type of question. Activate unlimited help now!

##### Intros
###### Lessons
1. Terms related to circles
• Diameter
• Circumference
• Central angle
• minor arc
• major arc
• Inscribed angle
• Chord
• perpendicular bisector
• Tangent
• point of tangency
2. How to find the length of an arc?
• by Central angle
• by Proportion
• by Using formula a = Θr

##### Examples
###### Lessons
1. Find the length of the arc in red.

2. In the following circle, AD is diameter and BC $\bot$ EF, and the radius is 7. Find the measures of:
1. $arc AB$
2. $arc ABE$
3. $arc AEC$
4. $\angle BFD$
3. On circle D, arcAB= 105°, arcBC= 140° and arcABC= 245°. Point E is on the circle D too and arcCE= 145°. Explain what E must be on ArcAB.