Step by step
The question
Question: change 3 radians to degrees.
1 Write the rule
Radians are another way to measure an angle.
A half turn is 180°.
In radians, a half turn is π.
So π = 180°.
We divide both sides by π.
One radian is 180° over π.
Careful!
To get degrees, π must cancel.
So π goes at the bottom.
2 Multiply
3 radians is 3 times one radian.
So we multiply by 180° over π.
Top times top: 540°.
3 Work it out
There is no π to cancel.
So we use the calculator: π is about 3.1416.
540 divided by π is about 171.887.
To the nearest tenth, 3 radians ≈ 171.9°.
4 Check
Let's check: go back to radians.
Times π over 180.
We get about 3: back to 3, close because we rounded.
So it is right!
Let's look back.
First: write the rule.
Then: multiply.
Then: work it out.
Last: check.