Spike's Calculators

Calculate the area and perimeter of a pentagram.

This calculator uses metres for measurements.

Pentagram = a five-pointed star that is formed by drawing the diagonals in a pentagon.

- the length of a side in metres
- decimal precision, the number of digits after the decimal point

- the area of the pentagram in square metres
- the area in square feet
- the area in square inches
- the perimeter of the pentagram in metres
- the perimeter in feet
- the perimeter in inches

A = √5(5-2√5w²/2 P = v*10 where A is the area of the pentagram P the perimeter of the pentagram v = s/((1+√5)/2) u = v/((1+√5)/2) w = v+u s the length of a side

one metre (m) = 3.28083989501312 feet (ft) one metre (m) = 39.3700787401575 inches (in) one square metre (m²) = 10.7639104167097 square feet (ft²) one square metre (m²) = 1550.0031000062 square inches (in²)