The formula is arc length=2(r)(360){\displaystyle { ext{arc length}}=2\pi (r)({
rac { heta }{360}})}, where r{\displaystyle r} equals the radius of the circle and {\displaystyle heta } equals the measurement of the arc's central angle, in degrees. This information should be given, or you should be able to measure it. Make sure you substitute this value for the variable r{\displaystyle r}. For example, if the circle's radius is 10 cm, your formula will look like this: arc length=2(10)(360){\displaystyle { ext{arc length}}=2\pi (10)({
rac { heta }{360}})}. This information should be given, or you should be able to measure it. Make sure you are working with degrees, and not radians, when using this formula. Substitute the central angle's measurement for {\displaystyle heta } in the formula. For example, if the arc's central angle is 135 degrees, your formula will look like this: arc length=2(10)(135360){\displaystyle { ext{arc length}}=2\pi (10)({
rac {135}{360}})}. If you are not using a calculator, you can use the approximation =3.14{\displaystyle \pi =3.14} for your calculations. Rewrite the formula using this new value, which represents the circle's circumference. For example:2(10)(135360){\displaystyle 2\pi (10)({
rac {135}{360}})}2(3.14)(10)(135360){\displaystyle 2(3.14)(10)({
rac {135}{360}})}(62.8)(135360){\displaystyle (62.8)({
rac {135}{360}})} Since a circle has 360 degrees total, completing this calculation gives you what portion of the entire circle the sector represents. Using this information, you can find what portion of the circumference the arc length represents. For example:(62.8)(135360){\displaystyle (62.8)({
rac {135}{360}})}(62.8)(.375){\displaystyle (62.8)(.375)} This will give you the length of the arc. For example:(62.8)(.375){\displaystyle (62.8)(.375)}23.55{\displaystyle 23.55}So, the length of an arc of a circle with a radius of 10 cm, having a central angle of 135 degrees, is about 23.55 cm.
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One-sentence summary -- Set up the formula for arc length. Plug the length of the circle's radius into the formula. Plug the value of the arc's central angle into the formula. Multiply the radius by 2{\displaystyle 2\pi }. Divide the arc's central angle by 360. Multiply the two numbers together.

Part of covering up the smell of smoke will involve keeping it contained. If the smoke drifts out of your room there is a chance that someone will smell it. Make sure any place smoke could escape through is completely covered up before smoking in your room. If you have any vents in your room cover them with a towel. Cracks under your door can release smoke from your room. These can be covered with a towel as well. Although the smell of smoke can be quite strong, introducing other scents in your room can help cover smoke up. These air fresheners won't likely remove the smell of smoke but they will make it less obvious. Review some of the following scents you can use to help mask the scent of smoke in your room: Deodorizing sprays will work best to cover up the smell of smoke in your room. Air fresheners or scented air sprays can help mask the smell of smoke. Burning incense can make the smell of other smoke less distinct. Don't overuse them as this can actually cause people to become suspicious. Although you may have kept the smell of smoke out of the air in your bedroom it will likely still cling to you. The smoky smell can stick to your hands, hair, and clothes and will be noticeable on your breath. Even if your room doesn't smell like smoke you should still make sure you yourself don't smell like it before going out. Wash your hands after smoking. Make sure your clothes don't smell like smoke. If your clothes smell consider changing them. Your breath will likely smell like smoke. Use mouth wash, brush your teeth, or at least eat a mint before leaving your room. You may want to shower after having a smoke to get the smell out of your hair. Cigarettes give of a highly noticeable smell that can get you caught if you are smoking indoors. Switching to vaporizers or e-cigarettes can remove the smell of smoke, allowing you to smoke indoors without much worry of being discovered. Many vaporizers are odorless or will have a much different scent than smoke.
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One-sentence summary --
Keep the smoke contained. Use air fresheners. Clean yourself up. Switch to e-cigarettes or vaporizers.