Area and Circumference of Circles

Seventh grade statisticians randomly select five states and then determine the mean area. The class then works together to create a dot plot of their results. 

This production, the second installment in a series of circles, demonstrates the process of finding the area of a circle. It is effective as an introductory tool. However, it needs to explain the reasoning behind the formula because that...

Looking at area with a hole. Using algebraic expressions as dimensions, learners see how to calculate the area of a rectangle that contains a square hole. The instructional video shows how to create a single expression for the area of...

With a little averaging, a trapezoid becomes a parallelogram. The section of an extensive geometry playlist shows how to derive the formula for the area of a trapezoid by changing it into a parallelogram. Using the formula, the video...

Find the square of the scale factor. A component of a large playlist on geometry discusses the ratios of the perimeters and areas of two similar polygons. The resource shows examples in finding the ratios that lead to a pattern.

Just how long is that rectangle? Pupils watch a short example on finding the base of a rectangle. The video shows how to use the formula for area to solve for an unknown measure knowing the other two.

While the lesson focuses on right triangles, this activity offers a great way to practice the area of all triangles through an interactive webpage. The activity begins with the class taking a square paper and cutting in in half; can they...

Trapezium or trapezoid is a matter location! A British narrator explains the process of finding the area of a trapezium, otherwise known as a trapezoid. After watching several examples, learners practice the skill with the included...

If one meter is 100 centimeters, how many square centimeters is equal to one square meter? Hint: the answer isn't 100! How many pupils make this mistake? A video lesson calculates the conversion factor of the common metric area units....

There are three variables in the formula for a parallelogram. Two of the values are given in this problem. Find the third value. Identify what each of the variables means. Match up the given values to the variables. Then solve for the...