# How do you find the measure of an arc?

Table of Contents

## How do you find the measure of an arc?

How do you calculate arc length without the angle?

- Divide the chord length by double the radius.
- Find the inverse sine of the result (in radians).
- Double the result of the inverse sine to get the central angle in radians.
- Once you have the central angle in radians, multiply it by the radius to get the arc length.

## What is the measure of arc BAC?

The measure of arc BC is 75 degrees. Remember that BD is a diameter. We know that there are 180 degrees in half of a circle. So to find angle BAC, we subtract 105 from 180 and get 75 degrees.

**What is measure of arc BEC in circle D?**

280° What is the measure of arc BEC in circle D? 134°

**How do you find the measure of an arc or central angle?**

The measure of an arc refers to the arc length divided by the radius of the circle. The arc measure equals the corresponding central angle measure, in radians.

### How do you find the measure of an arc with an angle?

An arc measure is an angle the arc makes at the center of a circle, whereas the arc length is the span along the arc. This angle measure can be in radians or degrees, and we can easily convert between each with the formula π radians = 180° π r a d i a n s = 180 ° .

### How do you find the measure of arc AB?

There are 360 degrees in any circle. The ratio of the angle ACB to 360 degrees will be 100/360 = 5/18. Thus, the length of the arc AB will be 5/18 of the circumference of the circle, which equals 2πr, according to the formula for circumference. length of arc AB = (5/18)(2πr) = (5/18)(2π(18)) = 10π.

**What is the measure of arc VX?**

39°

We know, the measurement of the external angle is the semi-difference of the arcs which comprises. Therefore, the measure of arc VX is 39°.

**What is the measure of arc PQ?**

66°

The measure of arc PQ is 66°.

#### What is the measure of arc AB 38?

Since arc AB subtends a central angle of 38°, the measure of arc AB is 38°.

#### What is the measure of angle BCD 37?

Angle BCD is a circumscribed angle of circle A. What is the measure of angle BCD? 37°, 53°, 74°, 106° Therefore, the measure of angle BCD is 74°.