An applet activity that provides an exercise in working with perimeter and area of 2D objects. The user is given a random figure and allowed to enter a value for the area and perimeter. Use the "How" and the "Why" button to assist you....

In Spanish. This site has a simple explanation on how to find the perimeter of a plane figure. It also contains an activity of following the path of a light and a brief biography of Oenopides de Chios.

Find a quick, concise explanation of perimeter. Perimeter formulas are given for common plane figures.

Recognize rays, lines, and line segments in geometric figures. Students receive immediate feedback and have the opportunity to try questions repeatedly, watch a video or receive hints.

Recognize parallel and perpendicular lines in geometric figures and pictures. Students receive immediate feedback and have the opportunity to try questions repeatedly, watch a video or receive hints.

Given a description of a sequence of transformations, determine whether it preserves segment length or angle measure. Students receive immediate feedback and have the opportunity to try questions repeatedly, watch a video, or receive hints.

Brush up on your math skills relating to cross-sections then try some practice problems to test your understanding.

[Free Registration/Login Required] This flipchart is an introduction to geometry vocabulary and elementary geometric figures. Activities ask students to match vocabulary and definitions and label figures. Assessment questions follow.

What began as a short overview is now a complete biography of the Red Baron, from his birth in 1892 to his early death in 1918. A graph of air victories by month is also supplied along with pictures of the famous planes.

View video footage from the scene of the plane accident that claimed the life of Polish President Lech Kaczynski, the first lady and key figures in the Polish Government. Was it pilot error, or that the Soviet-designed plane was more...

geometry

Describes, with illustrations, the basic two-dimensional shapes students will encounter in elementary Math.

In this lesson make a spinning top to explore the concepts of shape, color, spinning, and optical illusions.

In this lesson make a tangram and experiment with it to make new designs and pictures.

Diagrams and discussion of the "collection of 1-dimensional records" that make up a CAT scan.

This two-part geometry lesson plan has students identify, describe, and classify two-dimensional shapes. Students engage in hands-on activities including identifying shapes in the classroom, creating patterns with shapes, identifying...

Did you know that two-dimensional shapes are also called polygons? This lesson describes the various 2-D shapes and includes two interactive games to reinforce skills.

[Free Registration/Login Required] This flipchart helps students to analyze and compare various two-dimensional shapes according to the vertices, sides and parallel lines. It features "containers" created in Version 3 (can be used with...

In this set of worksheet activities, students will be guided to discover formulas for area of polygonal shapes and circles.

Students will discover factoring through the area of a rectangle.

Four basic geometric shapes - the triangle, parallelogram, trapezoid, and hexagon - are examined to determine how many of one shape fits "inside" another. For instance, how many triangles are "in" a hexagon. Ten questions with solutions...

This lesson will present how if two segments from the same point outside a circle are tangent to a circle, then they are congruent. It is 3 of 5 in the series titled "Two Lines Tangent to a Circle."

This lesson demonstrates how to determine properties of quadrilaterals by using triangles. It is 5 of 5 in the series titled "Using Triangles to Examine Quadrilaterals."

This lesson demonstrates how to use triangles to determine the sum of the interior angles of a polygon. It is 1 of 5 in the series titled "Using Triangles to Find the Sum of Interior Angles."