Number added to a code (such as a bar code or account number) to derive a further number as a means of verifying the accuracy or validity of the code as it is printed or transmitted.
An equilateral triangle has the following properties. 1  Equilateral triangles have three equal side lengths. 2  Equilateral triangles also have three equal angles of 60 degrees. 3  They also have three equal altitudes.  Is the height of an equilateral triangle equal to its side 1  length. The height is equal to side/2 x  â3.
Triangles can be classified according to the lengths of their sides: 1  An equilateral triangle has all sides the same length. An equilateral triangle is also a regular polygon with all angles measuring 60Â°. 2  An isosceles triangle has two sides of equal length. An isosceles triangle also has two angles of the same measure, namely the angles opposite to the two sides of the same length; this fact is the content of the isosceles triangle theorem, which was known by Euclid.