An ellipse is also called an oval and it is, essentially, an elongated circle. The distances from the center point to the side are not constant, which makes the formula for finding its area a little tricky. 

To use this formula, you must know:

The sum of these two points does remain constant. That is why we can use the following formula to calculate the area of any ellipse.

On occasion, you may see this formula written with r1 (radius 1 or semiminor axis) and r2 (radius 2 or semimajor axis) rather than a and b.

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Area and Perimeter of a Triangle

The triangle is one of the simplest shapes and calculating the perimeter of this three-sided form is rather easy. You will need to know the lengths of all three sides (a, b, c) to measure the full perimeter.

  • Perimeter = a + b + c

To find out the triangle's area, you will need only the length of the base (b) and the height (h), which is measured from the base to the peak of the triangle. This formula works for any triangle, no matter if the sides are equal or not.

  • Area = 1/2 bh
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Area and Circumference of a Circle

Similar to a sphere, you will need to know the radius (r) of a circle to find out its diameter (d) and circumference (c). Keep in mind that a circle is an ellipse that has an equal distance from the center point to every side (the radius), so it does not matter where on the edge you measure.

  • Diameter (d) = 2r
  • Circumference (c) = πd or 2πr

These two measurements are used in a formula to calculate the circle's area. It's also important to remember that the ratio between a circle's circumference and its diameter is equal to pi (π).

  • Area = πr2

Torque is a measure of the force that causes an object to rotate about an axis and is calculated as the cross product of radius and force.

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