Who invented angles

Chart protractor. A more complex form of protractor, designed for plotting the position of a ship on navigational charts, was invented in by Joseph Huddart, a U. This instrument, called a three-arm protractor, or station pointer, is composed of a circular scale connected to three arms.

To measure an angle you put the rough side of the protractor down then put the vertex of the angle in the little hole in the middle, shown on pages 3 and 4 and if the angle is acute you use the numbers on the bottom on the right but if it is acute but it is pointing to the left you use the left side and the top …. The small hole near the bottom of the protractor is aligned over the vertex of the angle to be measured.

Both scales go from 0 to , but they run in opposite directions. If the angle opens to the right side of the protractor, use the inner scale. If the angle opens to the left of the protractor, use the outer scale. The Mesopotamians passed their base numerical system to the ancient Egyptians, who used it to divide a circle into degrees, Mary Blocksma writes in her book Reading the Numbers. The degree circle worked out great: The Egyptians loved perfect triangles, and exactly six of them fit into a circle.

Therefore, six triangular slices of 60 degrees each made for a sensible degree dissection of a circle. The Egyptians, who invented the degree symbol, also came up with the first calendar based on a day year, which is only off by 5. Who were the first to use degrees in a circle and divide it to parts? Improve this question. Community Bot 1. So it rather accepted by many scientists and mathematicians that we could prefer degrees. Though 24 dividends are very helpfull for other calculations people on those managements side also accpeted.

Add a comment. Active Oldest Votes. Improve this answer. Though I was aware that Persian calendar wasn't days. The article had this implication on me that "Persian calendar is approximately degrees.

And every day Earth advances approximately one degree in its course around the sun. It is possible that he took over from Hypsicles, who earlier had divided the day into parts, a subdivision that may have been suggested by Babylonian astronomy. Show 2 more comments. Partha Shakkottai Partha Shakkottai 5 5 bronze badges. But 60 is too course, is better, better still. What we need is something fairly refined to begin with and submultiples thereof.

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