Pearson Geometry Common Core, 2011
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Pearson Geometry Common Core, 2011 View details
3. Permutations and Combinations
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Exercise 32 Page 842

A minor arc is an arc that measures less than 180^(∘). A major arc is an arc that measures greater than 180^(∘).

150 ^(∘)

Practice makes perfect

An arc is a portion of a circle defined by two endpoints. A central angle separates the circle into two arcs, the major arc and the minor arc. The measures of these arcs are related to the measure of the central angle.

Arc Measure
A minor arc is the shortest arc connecting two endpoints on a circle. The measure is less than 180^(∘) and is equal to the measure of its related central angle.
A major arc is the longest arc connecting two endpoints on a circle. The measure is greater than 180^(∘) and is equal to 360^(∘) minus the measure of the minor arc with the same endpoints.
In our case, we are given the measure of the major arc. Let's consider an example diagram.
We can use the formula from the table to find the measure of the minor arc m AB. m ADB = 360 - m AB We know the measure of the major arc mADB = 210, so we can substitute it into the above equation and solve for m AB.
mADB = 360 - mAB
210 = 360 -mAB
mAB + 210 = 360
mAB = 150
The measure of the corresponding minor arc is 150 ^(∘).