Spike's Calculators

# Pentagram - Metric

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.

### Pentagram Area and Perimeter - Metric

Point to Point Length m
Decimal Precision

#### Results:

###### Area of the Pentagram
Square Metres
Square Feet ft²
Square Inches in²
Metres m
Feet ft
Inches in

#### Calculation

1. the length of a side in metres
2. decimal precision, the number of digits after the decimal point

#### Results

1. the area of the pentagram in square metres
2. the area in square feet
3. the area in square inches
4. the perimeter of the pentagram in metres
5. the perimeter in feet
6. the perimeter in inches

##### Formula
```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
```

##### Conversions
```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)
```