The golden ratio (symbol is the Greek letter phi shown at left) is a special number approximately equal to 1.618.

The Fibonacci Sequence is the series of numbers: 0, 1, 1, 2, 3, 5, 8, 13, 21, 34, ... The next number is found by adding up the two numbers before it:

Plants can grow new cells in spirals, such as the pattern of seeds in this beautiful sunflower. The spiral happens naturally because each new...

Illustrated definition of Golden Ratio: The number approximately equal to 1.618033989... We get the Golden Ratio when a line is split into two parts so...

The Pentagram (or Pentangle) looks like a 5-pointed star. You may think it has something to do with witchcraft, but in fact it is more famous as...

Illustrated definition of Ratio: A ratio shows the relative sizes of two or more values. Ratios can be shown in different ways: using the...

Illustrated definition of Golden Mean: Another name for Golden Ratio: the number approximately equal to 1.618033989...

When we know the horizontal and vertical distances between two points we can calculate the straight line distance like this:

☐ Define the Fibonacci sequence and the Golden ratio and investigate the relationship between them.

When exploring the world around us we can measure lengths to find how long, how tall, how wide, or how far apart things are.