Trigonometry Examples

$- \frac{4}{5}$

Step 1

Convert the radian measure to degrees.

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Step 1.1

To convert radians to degrees, multiply by $\frac{180}{π}$ , since a full circle is $360 °$ or $2 π$ radians.

$(- \frac{4}{5}) \cdot \frac{180 °}{π}$

Step 1.2

Cancel the common factor of $5$ .

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Step 1.2.1

Move the leading negative in $- \frac{4}{5}$ into the numerator.

$\frac{- 4}{5} \cdot \frac{180}{π}$

Step 1.2.2

Factor $5$ out of $180$ .

$\frac{- 4}{5} \cdot \frac{5 (36)}{π}$

Step 1.2.3

Cancel the common factor.

$\frac{- 4}{5} \cdot \frac{5 \cdot 36}{π}$

Step 1.2.4

Rewrite the expression.

$- 4 \cdot \frac{36}{π}$

Step 1.3

Combine $- 4$ and $\frac{36}{π}$ .

$\frac{- 4 \cdot 36}{π}$

Step 1.4

Simplify the expression.

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Step 1.4.1

Multiply $- 4$ by $36$ .

$\frac{- 144}{π}$

Step 1.4.2

Move the negative in front of the fraction.

$- \frac{144}{π}$

Step 1.5

$π$ is approximately equal to $3.14159265$ .

$- \frac{144}{3.14159265}$

Step 1.6

Convert to a decimal.

$- 45.83662361 °$

Step 2

For angles smaller than $0 °$ , add $360 °$ to the angle until the angle is larger than $0 °$ .

$314.16337638$

Step 3

The angle is in the fourth quadrant.

Quadrant $4$

Step 4