The two figures that have same shape but different size are said to be similar. The angles of similar figures measure the same but corresponding sides are in proportion i.e when two figures are similar the ratio of the length of the corresponding sides are equal. Any two corresponding sides of two similar figures have a common ratio called the scale factor. The symbol ~ is used to represent corresponding similar sides.
The trapezoids ABCD and GHIJ are similar. So,
This means the length of sides of the trapezoid ABCD is 2 times the length of the sides of the trapezoid GHIJ.
The ratio of area of two similar figures is the square of the scale factor and the ratio of the volume of two similar figures is cube of the scale factor.