Children with expressive language disorder have difficulty conveying or expressing information in speech, writing, sign language or gesture. (For preschool children, the difficulty expressing themselves in writing is not evident, as they have not started formal education.)
A rectangle is defined as a parallelogram (a quadrilateral with two sets of parallel sides) with the non-parallel sides joining perpendicularly (at 90Â°). A square is a rectangle with the additional constraint the all four sides be of equal length.
1 In this case, the area within our rectangle is 4 Ã 3 = 12 square inches.  In the case of squares, since all four sides are the same, you can simply take the measurement of one side and multiply it by itself (also called squaring it or taking it to the second power) to get a square inches value for area.