K6 Math Logo
K6 Math Logo
K6 Math Logo
trapezoid

Master the Isosceles Trapezoid from recognition to construction.


The Isosceles Trapezoid can sometimes cause quite a bit of confusion. This is because people often refer to it as simply a Trapezoid, but as you will see from this page, even though it is a trapezoid, it has some extra special features making it an isosceles shape.




The seven steps detailed bellow take you from basic identification all the way through to taking a detailed look at the theorems involving the isosceles trapezoid. These steps also include 'pit stops' to complete fun geometry projects and coloring sheets.

These are nice 'breathers' on the learning curve, but they are excellent ways of reinforcing the new knowledge in ways that your kid can get a real life, hands on approach to understanding the basic geometry concepts included.

Okay, so let's get started ...
3r grade math worksheets

Identify

How do we know what we look at is an Isosceles Trapezoid?

First and fore most it is a quadrilateral which is a 4 sided plane shape.
  • It has 4 lines
  • Two of the lines are paralell
  • The other two lines are equal in length.
  • The angles at its base are equal.
  • The remaining two angles are equal.
  • It is a Simple Quadrilateral (The sum of its angles is 360 degrees
  • An Isosceles Trapezoid is also a Trapezoid.


The table bellow is intended to be read from left to right. Chose any shape from the left hand column, and by moving right, you can see what other shape qualities it posesses.


Simple

Quadrilaterals

Square
Rectangle
Parallelogram
Isosceles Trapezoid
Trapezoid
Rhombus
Kite
Square
X
X
X
X
X
X
X
Rectangle
X
X
X
X
Parallelogram
X
X
Isosceles Trapezoid
X
X
Trapezoid
X
Rhombus
X
X
Kite
X

Once your child is comfortable with how to recognize the shape, offer them some shape worksheets to see how they get on with identifying the shape when compared with others. You may also find our Quadrilateral Family Tree Printable a useful tool to offer your child.
Kindergarten math

Calculate Area and Perimeter

How to calculate the Area and Perimeter of an Isosceles Trapezoid


Please note this is NOT a formula your K-6 grade student is required to know.
These images are of a Trapezoid, but the formula for these two shapes are the same.





The Area of this type of trapezoid is calculated by first getting the AVERAGE length of the two sides that are parallel. Then you multiply this average by the altitude (height) of the shape. If your child has problems understanding the concept of Area, I recomend working with second grade 'grid method' worksheets first, and then move on to fourth grade worksheets using numbers and finally word problems.
perimeter of trapezoid
The Perimeter of ANY shape is simply the sum total of all the lengths of the shape.
The perimeter of a trapezoid is the sum of its length.




Kindergarten math

How to construct a Trapezoid

To complete this, you will need a ruler, pencil, compass, protractor, and a blank piece of paper!


Note: This construction is based upon having the knowledge of the height of the trapezoid along with the angles at its base.
Step 1: Draw a straight line lightly using your ruler and pencil on your paper. - This is what we call a construction line, and will be the base of your trapezoid.
Step 2: Indicate the two end points of the base of your shape with two points, measured by your ruler.
Note:We know that the top and base line of your trapezoid are parallel, and, we know the distance between them (the height of your shape)
Step 3: Using your compass, construct two lines (lightly) perpendicular to your base. On both of these lines measure the height of your trapezoid, and indicate with two points (one on each perpendicular) Connect these two points using a light construction line. The second side of your trapezoid will be 'somewhere' on this line.
Step 4:Using your protractor, measure the angles at the base, using the points on your first construction line and construct your third and fourth sides.
Note: You will now have four construction lines, intersecting at four vertices.
Step 5: Your isosceles trapezoid is the shape contained between the four points of intersection of these four lines.
Step 6:Using a heavier line connect the four points to finish your shape.

construct a trapezoid construct a trapezoid
Kindergarten math

Relationship to 3D Shapes

There are no 3d Figures an elementary student will have to stude in relation to the isoscoles trapezoid. HAVING SAID THIS, it is a good idea for you as a parent/tutor to have your child draw or deconstruct 3d shapes from any and all 3d shapes that they do have to deal with, such as the Cuboid and the triangular prism. Fine tuning this skill will be of endless benefit to them in their geometry studies at a later time in their academic careers. Bellow is a diagram of a trapezoidal prism, deconstructed into two triangular prisms. and a Cuboid
Trapezoid Prism

It would also be a very good idea to compare this type of trapezoid to other quadrilaterals as well as the isoscoles triangle.
Kindergarten math

Geometric Coloring Sheets

The use of coloring sheets allows your child to start experimenting with different shapes. A great first step is to encourage your child to color in shapes adjacent to eachoter with the same color, until their shape starts to look like 'something'. Perhaps that something will be a rectangle or a house. By doing this, your child will start to realize the connection between the shapes. You will find some nice free geometric coloring pages to download here.
Kindergarten math

Fun Geometry Projects

COMMING SOON!


Kindergarten math

Theorems & Proofs

COMMING SOON!








Return from the isoscoles trapezoid to our Polygon Section.or our Quadrilaterals Section.
Or
Go to K6 Geometric Shapes Home Page, to explore all the other great sections I have to offer.



If you have any suggestions on how to make this site better for you and other readers, please don't hesitate to contact me. I love to hear from my readers, and with a little feedback, I can make this a great resource for parents, teachers and tutors alike.




Looking for something?

Custom Search
Subscribe To This Site
XML RSS
Add to Google
Add to My Yahoo!
Add to My MSN
Subscribe with Bloglines












Copyright© 2008-2012.

Template Design