Scholastic
Study Jams! Area of a Triangle
Even though there is a wide variety of different triangles in the world, knowing a single equation allows us to find the area of each and every one of them. Follow along with this step-by-step presentation as Zoe clearly models how to...
Shodor Education Foundation
Triangle Area
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...
Illustrative Mathematics
Area of a Trapezoid
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...
Curated OER
Finding the Area of an Equilateral Triangle
The problem seems simple: find the area of the equilateral triangle whose sides are each length 1. In fact, this same problem is solved in 8th grade, addressing a different Common Core standard, using the formula for area of a triangle...
Illustrative Mathematics
Finding Areas of Polygons, Variation 1
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...
Curated OER
Area of Right-Angled Triangles
There's a trick to solving the area of a triangle, and it involves a skill your geometers have already mastered. Help them discover the connection between finding a rectangle's area and finding a right triangle's area as they solve for...
Corbett Maths
Pythagoras Rectangles and Isosceles Triangles
When does the Pythagorean Theorem come in handy? An intriguing video uses the Pythagorean Theorem to solve problems other than simply finding the length of a side of a right triangle. Pupils find the diagonal of a rectangle and the...
Curated OER
Principles of Square Roots Lesson Plan
Middle and high schoolers investigate all the different places in math that square root is present. For this geometry lesson, pupils discuss square roots as it relates to a right triangle and construction. They go over altitude, rise,...
Curated OER
Investigating Segments in a Right Triangle
High schoolers explore the concept of right triangles as they construct a right triangle using Cabri Jr. Learners find the midpoint of the hypotenuse and construct a line from the midpoint to the vertex of the right angle. They then...
Curated OER
Area of a Triangle: English Learner 16.4
In this ELL triangle worksheet, students review the definition of a triangle and then draw dotted lines to show the height of each figure. If one side is the height, students circle that side.
EngageNY
Perimeter and Area of Triangles in the Cartesian Plane
Pupils figure out how to be resourceful when tasked with finding the area of a triangle knowing nothing but its endpoints. Beginning by exploring and decomposing a triangle, learners find the perimeter and area of a triangle. They...
Mathed Up!
Area of Compound Shapes
Scholars learn how to determine the area of compound shapes by finding the areas of the basic shapes that make it up. Pupils find the areas by adding areas together or subtracting them.
Noyce Foundation
Lyle's Triangles
Try five problems on triangles. Levels A and B focus on shapes that can be created from right triangles. Level C touches upon the relationship between the area of a six-pointed star and the area of each triangle of which it is composed....
EngageNY
Using Trigonometry to Determine Area
What do you do when you don't think you have enough information? You look for another way to do the problem! Pupils combine what they know about finding the area of a triangle and trigonometry to determine triangle area when they don't...
Curated OER
Special Right Triangles
Using the Pythagorean Theorem to solve for missing angles, students evaluate right triangles and their properties.
Curated OER
Finding the Area and Perimeter of Polygons
Seventh graders practice finding the area and perimeter of polygons. In this polygon area lesson, 7th graders brainstorm shapes and take a walk to locate shapes. Students record properties of shapes and use various shapes to make a...
West Contra Costa Unified School District
Finding the Equation of a Circle
Tired of going around and around for a resource on circles? Scholars determine the general equation of a circle on a coordinate plane, then participate in an activity matching equations to the radii and centers of the circles...
Curated OER
Area of Triangle - Problem Solving 16.4
In this area of triangles worksheet, students find the area of each triangle in the word problems. Students complete five problems.
Curated OER
Area of Triangles - Word Problems
Here is an area of triangles practice activity in which learners sharpen their problem solving skills as they solve six story problems.
Illustrative Mathematics
Base and Height
It is easy to find the area of a triangle where the base and the height are given. But in this resource, it is up to your geometers to identify the base and height of the triangle. In fact, your pupils will learn that there are three...
Alabama Learning Exchange
What You Know About the Bermuda Triangle?
Get lost in the classifications. Using the backdrop of the Bermuda Triangle, pupils classify it by angle and side measures. They also learn information about the triangle and its history.
Illustrative Mathematics
Same Base and Height, Variation 2
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...
Shodor Education Foundation
Squaring the Triangle
Teach budding mathematicians how to square a triangle with an interactive that shows a graphical proof of the Pythagorean Theorem. Pupils alter the lengths of the legs using sliders. Using the inputted lengths, the applet displays the...
Inside Mathematics
Circles in Triangles
Challenge the class with inscribed circles in triangles. The assessment task requests class members use their knowledge of circles and right triangles to prove two triangles are congruent. They go on to utilize their knowledge of...