Formula for Volume of a Pyramid or Pyramid Section
To find the volume of a pyramid or pyramid section, the Egyptians used the following algorithm. This method is not perfectly accurate, but it does provide a very good estimate.1. square top edge 2. square bottom edge 3. multiply top edge by bottom edge 4. add results of 1, 2 and 3 5. find 1/3 of Height 6. multiply results of 4 and 5 together |
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Formula for area of a circle
The Egyptian method for finding the area of a circle is similar to the one for the volume of a pyramid in the fact that it is not entirly accurate but quite close. The Egyptians applied "close enough" in these two formulas as well as with their fractions. The algorithm is,
1. take 1/9 of diamiter 2. subtract result of 1 from diamiter 3. square the answer |
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Formula for Multiplication
To Multiply numbers, the Egyptians used the following method,1. make three columns A, B, and C 2. place one number being multiplied at bottom of A 3. place the other at the top of C 4. put 1 at the top of B 5. double the value of B, repeat this step until B is as large as possible without being greater than A 6. put the new B values in the B column in descending order 7. double the value of C once for every time B is doubled 8. put in the new values in the C column in descending order 9. subtract the largest availible B value from the A value, if this would make A less than zero, cross out the row and move to the next. repeat this step untill all B values have been tested. 10. add up all the C values that have not been crossed out. This is the answer |
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Formula for Division
The Egyptians used a similar formula for division as they did for multiplication The difference is that the B and C columns are switched as in this example of 30/5, in all other respects the formula is the same.A | B | C |
cross out | 5 | 1 |
0 | 10 | 2 |
10 | 20 | 4 |
cross out | 40 | 8 |
cross out | 80 | 16 |
30 |
Egyptian and modern formulas for slope
The modern formula for slope is rise over run or deltaY/DeltaX. To find slope by the modern method, you take two points, find their x and y values and plug them into the deltaY/deltaX equation as in this example.point 1 | = | (1,1) | point 2 | = | (3,2) |
3-1 | 2 | ||||
--- | = | - | |||
2-1 | 1 |
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2 | 1 | * | 7 | 7 | ||
- | changes to | - | = | - | ||
1 | 2 | 2 |