Perpendicular

Lines or planes that meet at a right angle (90°) are said to be perpendicular.

The symbol above is often used to identify 90° angles on a diagram.

1D/2D/3D (Dimensions)

Refers to the number of coordinates needed to plot a point in a given space.

Plotting a point on a number line would require just one value hence 1D.

Plotting a point on a plane set of axes would require two coordinates (x and y) hence 2D.

Never start a conversation with π

It will just go on forever.

Inequalities

x < y means x is less than y

x > y means x is more than y

x ≤ y means x is less than or equal to y

x ≥ y means x is more than or equal to y

Zero

It is widely accepted that the number 0 was born in India. Indian scholars were the first to draw a symbol to represent 0, a figure that does not appear in Greek manuscripts or Roman numerals.

26

The only number trapped between a square number (25) and a cube number (27).

No other number meets that condition.

Why didn't Romans find Algebra challenging?

Because X was always 10

Polygon

A plane figure of three or more points connected together by straight lines to form a closed shape. The points are often referred to as vertices while the straight lines are called sides or edges.

Examples of polygons are triangles, quadrilaterals etc...

Currency

The money in current use within a country. The euro (€) is the currency used in many European countries like France or Germany.