Whats the difference between radians and degrees?

Thread Starter

RRITESH KAKKAR

Joined Jun 29, 2010
2,829
Degrees are used to express directionality and angle size. If you stand facing directly north, you are facing the direction of zero degrees, written as 0°. If you turn yourself fully around, so you end up facing north again, you have "turned through" 360°; that is, one revolution (one circle) is 360°.

Aside: Why is one revolution divided into 360 parts called "degrees"? Because the ancient Babylonians, now four- or five-thousand years dead, viewed the numbers 6, 12, and 60 as having particular religious significance. It is because of them that we have twelve-hour nights and twelve-hour days, with each hour divided into sixty minutes and each minute divided into sixty seconds. And "once around" is divided into 6×60 = 360 parts called "degrees".
 

hexreader

Joined Apr 16, 2011
581
  • Convert 43.1025° to DMS form.
?
I have a brilliant idea!

Instead of waiting for HP to spoon-feed you the answer, how about you research this question yourself.

Google will tell you all that you need to know to come up with the answer for yourself.

Requires that you think for yourself, but you will be proud of yourself afterwards.

How about it?
 

Thread Starter

RRITESH KAKKAR

Joined Jun 29, 2010
2,829

  • I can see that I have 43°, but what do I do with the "0.1025" part? I treat it like a percentage of the sixty minutes in one degree, and find out how many minutes this is:

    • (0.1025 degrees)(60 minutes / 1 degree) = 6.15 minutes
    ...or 6 minutes and 0.15 of a minute. Each minute has sixty seconds, so:

    • (0.15 minutes)(60 seconds / 1 minute) = 9 seconds

  • Then 43.1025° = 43° 6' 9"
 

Thread Starter

RRITESH KAKKAR

Joined Jun 29, 2010
2,829
π

π=22/7
as i was taught it is constant
or The number π is a mathematical constant, the ratio of a circle's circumference to its diameter, commonly approximated as 3.14159.
 

pgs

Joined Dec 20, 2015
6
Exactly right. As I said in a caffeine induced answer the other week. Our number system cannot accurately represent pi. Just leave it as pi and know it as the ratio of circumference to diameter of any perfect circle.

If people are desperate for an approximation they can try one of the following:

π ~ 22/7 [this ratio was taught in schools but was never supposed to be anything more than a half decent approximation. It lived in a world without calculators and computers before decimal fractions ruled the roost]

π ~ 355/113 [another decimal ratio that is a bit closer to pi than 22/7 but still an approximation]

π ~ "How I wish I could calculate pi" [count the letters in each word to get an approximation of pi to six decimal places]

π ~ The number that is shown on a calculator when the π button is pressed [as pi is an irrational number it goes on forever in reality - the limited decimal places on a calculator stop way too early]
 
Last edited:

WBahn

Joined Mar 31, 2012
30,058
Why Early people or mathematician start choosing 360degree in rotation of one circle?
what is it root of 360*
Well, let's see what someone in this thread has already said on this very point:

Aside: Why is one revolution divided into 360 parts called "degrees"? Because the ancient Babylonians, now four- or five-thousand years dead, viewed the numbers 6, 12, and 60 as having particular religious significance. It is because of them that we have twelve-hour nights and twelve-hour days, with each hour divided into sixty minutes and each minute divided into sixty seconds. And "once around" is divided into 6×60 = 360 parts called "degrees".
Why ask a question that you, yourself, have already provided an answer for?
 
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