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Elementary Archive

Browse Elementary Triangles and Other Polygons

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A 14-Sided Polygon [7/28/1996]

What is the proper name for a 14-sided figure?

7-, 9-Sided Polygons [9/13/1996]

What is the name of a 7-sided figure? a 9-sided figure? Is one of these ever called a septagon? If "septi" means seven, why is September the 9th month of the year?

Area and Perimeter [05/01/2001]

I do not understand area and perimeter - can you explain them?

Area of a Parallelogram [01/07/1999]

How can the area of a parallelogram be the same as the area of a rectangle?

Areas of Figures Broken into Rectangles [10/17/2001]

Calculate the area of each figure. First divide the figure into rectangles and squares...

Area: Triangle vs. Rectangle [4/30/1996]

Why do you have to use a different formula to get the area of a triangle than a rectangle or square?

Area vs. Perimeter of Rectangles [03/19/2000]

Can you explain how two rectangles with exactly the same perimeter can enclose different areas?

Are Squares Rectangles? Are Rectangles Squares? [03/29/2004]

Can a rectangle be a square? I just was wondering because I know a square can be a rectangle.

Axes of Symmetry [2/3/1996]

Can you help a year 5 student understand axes of symmetry of a triangle?

Concave and Convex Polygons [08/13/2001]

What's the difference between a convex and a concave polygon?

Decagons [05/04/1997]

What does a decagon look like?

Defining the Term Oblong [05/15/2000]

Can you give a definition of the term "oblong"?

Describing a Rhombus [01/17/1997]

What is a rhombus?

Distance Between Opposite Corners of a Box [05/09/2002]

A moth is sitting in the lower left front corner of a storage shed. What is the length of the shortest path that the moth can fly to the upper right back corner of the shed?

Equable Shapes [04/26/2001]

Is there a rule for how to get equable shapes, that is, shapes with the same area and perimeter?

Equilateral, Isosceles, Scalene - Word Origins [12/09/2001]

I need to find out about the origins of the scalene, isoceles, and equilateral triangles. How they were named?

Etymology of the Word Rectangle [02/07/2003]

Where does the word 'rectangle' come from?

Etymology of the Word Rhombus [01/30/2003]

Where does the word rhombus come from?

Finding the Perimeter and Area [12/01/1998]

I don't understand how to do perimeter and area in shapes such as a parallelogram and trapezoid.

Finding Total Area of Several Rectangles [07/08/2005]

I need to find the total square footage of a lot of rectangular lawns. Do I have to find the area of each lawn and add up all the areas, or can I just add all the lengths and all the widths and make one area calculation based on those two totals?

How Many Border Stamps? [04/17/2001]

How many stamps are on the border of a 10x10 sheet of 100 stamps?

How to Make a Square with Three Lines [06/19/2001]

My teacher says it is possible to make a square with three lines, but I don't know how to do it. Can you help me?

How Wide is the Garden? [01/06/1998]

A rectangular garden has a 136-ft. fence around it. The garden is 40 feet long. How wide is it?

Is a Square a Rectangle? [06/04/1997]

Are squares rectangles? What is a pentagon?

Is a Square a Rhombus? [8/30/1996]

I've come across different definitions of a "rhombus" that make it unclear whether a square is a rhombus.

Is Kite the True Name? [03/29/2002]

Is kite the true math name for this shape, or is there another?

Kites And Triangles [11/02/1998]

What are kites, and how are they related to triangles?

Leg of a Triangle [04/02/2002]

I need to know where the name "leg" of a triangle comes from, or what its origin is.

Letter Names for Triangles [05/16/2000]

When a triangle is named by the letters of its vertices, why are the letters in the order they are? Could they be in any order?

Logo Area [03/26/2003]

How do we find the area in square units following a Logo command?

Making a Parallelogram [06/19/2001]

Make five shapes - a parallelogram, a square, and three triangles - into one parallelogram.

Name That Polygon [12/03/1999]

Can you help me figure out what kind of polygons are being described based on these clues?

Nonagon or Enneagon? [02/06/2003]

Is 'enneagon' really the correct name for a 9-sided polygon?

Pentagram [12/08/2001]

Is a five-pointed star on a flag a decagon? Or just five triangles?

Picture of Icosahedron [7/31/1996]

Do you have a picture of an icosahedron?

Polygon Diagrams [05/11/2003]

I would like to see pictures of polygons with 11, 12, 13, 14, and 15 sides.

Polygon Names [09/18/2001]

Why is a 3-sided polygon called a triangle instead of a tri-gon? Why is a 4-sided polygon called a quadrilateral instead of a tetragon, when all the others are ___-gons? Why is there not a single consistent term?

Pythagorean Theorem [5/14/1996]

What is the Pythagorean theorem?

Quadrilateral Classification: Definition of a Trapezoid [01/15/1997]

What is the correct definition of a trapezoid, and why?

Quadrilaterals [8/31/1995]

What is 4-sided and has no equal angles?

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