How to Learn Quadrilateral Shapes

Quadrilateral shapes are all around us from street signs to furniture. To learn the basics of quadrilateral shapes, you'll need to understand the various classifications of quadrilaterals. You'll also benefit from becoming familiar with mathematical formulas used to measure these shapes. Becoming comfortable with methods of measuring quadrilaterals can come in handy in areas like figuring square footage of a room or house, and measuring fabric for a sewing project.

Difficulty: Easy

Instructions

Things You'll Need:

• Calculator (optional)

Understanding Quadrilaterals

1. Familiarize yourself with the definition of quadrilaterals. Quadrilateral shapes are any two-dimensional shapes having four straight sides and four corners. Quadrilaterals are sometimes called "tetragons" or "quadrangles." Special quadrilaterals include the square, rectangle, rhombus, parallelogram, kite and trapezoid. Any quadrilateral that isn't included in this list is known as "irregular." The angles of any parallelogram add up to 360 degrees.

2. Learn the parallelogram. This is a quadrilateral that has two sets of parallel sides, with opposite sides and angles being equal. Parallelograms also include squares, rectangles and rhombuses. Find the perimeter of a parallelogram by adding the lengths of all four sides. Figure the area by measuring the length times the height.

3. Learn about rectangles. Rectangles have four sides; the opposite sides are equal in length and parallel. Each of the four angles equals 90 degrees. The perimeter is obtained by multiplying one side by 2 and an adjacent side by 2 and then adding the two answers. The area equals base times height.

4. Become familiar with squares. Squares have four equal sides and four equal angles. Each angle is 90 degrees. A square also is included in the categories of rhombus and rectangle. To figure the perimeter of a square, multiply the length of one side times 4. To find the area, square the length of one of the sides; that is, multiply that number times itself.

5. Learn about the rhombus. Rhombuses have four sides that are equal. The angles opposite each other are equal as well. If you draw two lines, each one running from one angle to the opposite angle, the lines intersect each other at 90-degree angles. The perimeter and area of a rhombus are figured in the same way as those of a square.

6. Familiarize yourself with the trapezoid. This four-sided shape has only two sides that are parallel. If both of the sides that aren't parallel are equal in length, the shape is an isosceles trapezoid. Find the perimeter of a rhombus by adding the lengths of all the sides. Figure the area by adding the lengths of the two parallel sides and multiplying that sum by half of the height.

References

• "Quadrilaterals." Retrieved July 27, 2009, from the Math is Fun website.
• "Geometry Formulas." Retrieved July 27, 2009, from the Math website.

Who Can Help Sponsored

• Earn your degree from industry experts at University of Phoenix. Take the next step in your career.