Find the area or perimeter of shapes like triangles, rectangles, parallelograms, and hexagons on the coordinate plane. Students receive immediate feedback and have the opportunity to try questions repeatedly, watch a video or receive hints.

Three circles are mutually tangent. Students are asked to find the total area of the circles plus the area inside where they meet. Students will need to know how to calculate the area of a circle, a sector of a circle, and an equilateral...

The purpose of this task is for students to practice plotting points in the coordinate plane and finding the areas of polygons. This task assumes that students already understand how to find areas of polygons by decomposing them into...

Find the areas of shaded regions which are combinations of squares, triangles, and circles. Students receive immediate feedback and have the opportunity to try questions repeatedly, watch a video or receive hints.

Use this calculator to find the sides, perimeter, area, semiperimeter, and altitude of an isosceles triangle.

[Free Registration/Login may be required to access all resource tools.] Find the area of a triangle when all three sides are known.

In this Computer Algebra System (CAS) activity, students use 'landscape' paper and fold the top left corner of the page so that it just touches the bottom of the page. They calculate the area of the triangle formed by the bottom left...

Eighth graders are presented with a drawing of a large square inscribed by a circle which is itself inscribed by a second square. They are asked to find the area of the circle outside the smaller square and compare it to the area of the...

A challenging proof like geometry of finding the square inscribed in a triangle.

This activity allows students to find the area of a triangle using Heron's formula.

[Free Registration/Login Required] This flipchart is a review of calculating the area of squares, rectangles, and triangles for fifth graders. It also includes problems that work backwards from the area to find missing dimensions. It...

This MathWorld site offers a lesson on finding the midpoint of a line segment using a compass and finding the midpoint of the sides of a triangle. This site also has an interesting way of drawing two triangle with equal area by finding...

Based off of the hit television show NUMB3RS, this lesson introduces students to Voronoi diagrams, which split a plane into regions corresponding to distances to given points. The lesson is framed in the context of splitting a city into...

A problem of finding the fraction of a square that is shaded given criterion. Students will have to use their mathematical reasoning and triangle solving skills to solve this area problem.

Jerry and Ashley are trying to find out if it is possible to see the lowest point in the USA from the highest point in the USA. It turns out that the highest point in the United States, the peak of Mount Whitney, is only 85 miles from...

Seventh graders find the area of regular polygons, recalling what they already know about the area of geometric shapes and generalizing a formula for any regular polygon.