While the instructional activity 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...

Here is a straightforward example of how to apply the Pythagorean Theorem to find an unknown side-length of a trapezoid. Commentary gives additional information on proving that the inside of the trapezoid is a rectangle, but is...

Third graders are exposed to finding the area of polygons by decomposing figures and recomposing them into rectangles. This strategy allows children to expand on their prior knowledge of constructing shapes by rearranging parts into...

An exercise in finding the area of polygons by decomposing into triangles and composing into rectangles is the focus of this resource. Make several copies of the worksheet for each participant. Ask learners to use colored pencils to...

What makes a good sample? Your classes collaborate to answer this question through a task involving areas of rectangles. Given a set of 100 rectangles, they sample a set of five rectangles to estimate the average area of the figures. The...

Tip the scale in your favor when learning about scale factors. After viewing a video clip of a learner trying to determine the scale factor of the areas of two rectangles, scholars consider how changing the dimensions of a rectangle...

An excellent activity that effectively pulls together the concepts of area, fractions, and equivalent fractions! Using 3x2 rectangular arrays, 3rd graders are introduced to the concept of area in terms of square units. Building on this...

A deceptively simple question setup leads to a number of attack methods and a surprisingly sophisticated solution set in this open-ended problem. Young geometers of different strengths can go about defining the solutions graphically,...

An excellent lesson that encourages learners to discover how complex figures can be broken into simpler shapes when measuring area. Working with block letters, learners are given the freedom to develop their own strategies for...

Just how big of a TV do you need?! The task at hand asks individuals to compare the area of 80-inch and 55-inch TVs. The length of the TV is given and learners must use the Pythagorean Theorem to determine the width to calculate the areas.

The asteroid is getting closer and the question is whether the state of Alabraska is large enough for the shelter calculated in the previous activity. Teams determine the scale of their project and then use the scale on the map to...

You don't need a scale to determine weight. This activity provides a way to use the concepts of air pressure and surface area to determine the weight of a vehicle by calculating the amount of weight each tire supports.

This is a good model for learners to visualize triangles of the same base and height. They can can begin to comprehend that these triangles will have the same area no matter how the triangle is drawn. It is part of a series of resources...

Gaining practice in translating a verbal description into a diagram and then an equation is the real point of this similar triangles exercise. Once the diagram is drawn, multiple methods are provided to reach the conclusion. An effective...

Don't let your classes get stuck on area calculations—grab their attention with an inquiry-based lesson! Scholars must develop a plan to determine how may sticky notes it takes to cover the surface of a door. They decide on the...

You won't want to flush a great lesson down the drain! An intriguing resource asks learners to predict the number of sheets of toilet paper on a roll. Presented with the dimensions of the roll and one sheet of paper, scholars make...

Four triangles are depicted for learners to construct on a geoboard. They compute and compare the areas, and so meet one of the sixth grade Common Core standards for geometry. Note that the set of triangles does not include a right...

You can't go wrong with Star Wars! A video set to the Star Wars theme song presents a problem solving situation. The task? Determine how many small Post-It notes will fit on a bulletin board. The problem requires individuals to compare...

Roll out the red carpet for an exemplary lesson. Using the dimensions of a rolled piece of carpet, learners calculate the dimensions of the flat sample. Pictures provide individuals with the information they need to make a valid conclusion.

Learners follow a series of instructions for drawing and coloring different shapes in order to learn the difference between the perimeter and area of a polygon. Then they are asked to find the perimeter and area of a 3x4 rectangular...

Investigate polygons from rectangles to triangles to octagons. Each level of the five-problem series targets a different grade level. Beginning with the level A problem, learners examine the relationship between area and perimeter by...

Is it possible for a rectangle to have the same area and perimeter? If you disregard units, it happens! In a challenging task, groups work to determine the rectangles that meet these criterion. The hope is that learners will naturally...

This is an interesting geometry problem. Given the figure, find the area of a triangle that is created by the intersecting lines. The solution requires one to use what he/she knows about coordinate geometry, as well as triangle...

Scholars crave practical application. Let them use the different models of a quadratic function to plan the size and shape of a school playground. They convert between the different forms and maximize area.