Mathematics Class

PROPORTION:

The homotecias are joined with an interesting topic called the proportion. More than joined to the topic is a property of the homotecias, without proportion there’s no homotecia. So, what is the proportion?

The proportion: A proportion is a name we give to a statement that two ratios are equal. It can be written in two ways:

• two equal fractions, 

Or,

•   a:b = c:d

To check that between two ratios is a proportion you can do by many ways, there’s exactly 10 ways sometimes are easiest than other ways. The easiest way to find the proportion is to multiply the extremes and the medios  it had to show the same result.

When two ratios are equal, then the cross products of the ratios are equal.

That is, for the proportion, a:b = c:d ,  a x d = b x c       

      
        

SIMILARITY:

Two geometrical objects are called similar if they both have the same shape. More precisely, either one is congruence. When there are two geometrical objects and don’t change his angles it calls similarity. It does not mean that the size had to be the same, it would be equally. In basic words it can change the form and the direction of the object but it cannot change his angles.

CARTESIAN COORDINATE SYSTEM:

A Cartesian coordinate system specifies each point uniquely in a plane by a pair of numerical coordinates, which are the signed distances from the point to two fixed perpendicular directed lines, measured in the same unit of length. Each reference line is called a coordinate axis or just axis of the system, and the point where they meet is its origin, usually at ordered pair (0, 0). The coordinates can also be defined as the positions of the perpendicular projections of the point onto the two axes, expressed as signed distances from the origin.

To find the coordinates you have to read the numbers inside the parenthesis, like: (1, 8)

You had to find the one in the (X) side, the horizontal side. Then you had to find the8 in the (Y) side, the vertical side.

It can be positive numbers ore negative numbers also, it depends on the symbol.

POSTED BY: NICOLAS GARCIA RUBIANO.  7B