Curated OER
Using Trigonometry to Find Area
In this Algebra II/Trigonometry instructional activity, students use trigonometry to determine the area of a triangle or a parallelogram. The one page instructional activity contains ten problems. Answers are not provided.
Alabama Learning Exchange
Polygons-Changing Area Versus Changing Perimeter
Investigate the area and perimeter of polygons in this geometry lesson. Young geometers use grid paper to draw a quadrilateral and calculate its area and perimeter. They also read The Greedy Triangle to identify the changing shape of...
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...
Corbett Maths
Area under a Graph
What? The calculation of area is a linear distance? A short video shows how to use the areas of simple polygons to estimate the area under a graph. Pupils divide the area under a curve into figures to easier calculate the area. Given...
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...
Curated OER
Perimeter and Area
Use this perimeter and area worksheet to have learners find the perimeter and area of shapes with right angles. They complete a total of nine problems.
Curated OER
Coordinate Planes - Area of Triangle
In this online math worksheet, students find the area of a variety of triangles given the measurements of their vertices. This excellent resource allows the students to check their answers, and to get "hints" should they run into...
Curated OER
Area Of Triangles
In this math worksheet, students complete 19 problems where they find the area of triangles by utilizing a variety of shapes and numbers. This worksheet would be an excellent homework assignment.
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...
Curated OER
Similar Triangles and Trapezoids, and Circles
High schoolers answer two problems involving area of shaded regions. Students then answers six questions involving perimeter, area, and circumferences. The remaining two questions involve ratios of similar figures.
Curated OER
Finding the Area of Shapes
In this area of shapes unit, upper graders participate in hands-on problem solving activities to find the formulas for the area of a parallelogram, a triangle, and a trapezoid. They manipulate the geoboard to explore relationships among...
Curated OER
Ratios for Area and Volume
In this ratios for area and volume worksheet, students solve problems where they find the ratios for problems of shapes dealing with area and volume. Students complete 4 problems.
Texas Instruments
Identifying a Triangle by its Sides and Angles
Identify triangles by their angle measures and side lengths by looking at and measuring angle measures and side lengths. Use Cabri Jr. to construct various triangles, then manipulate the construction to create the 6 types of triangles,...
Curated OER
The Pythagorean Theorem and Classifying Triangles
Through the examination of the relationship between the lengths of the sides of a triangles high schoolers will learn the classification of triangles (acute, right, or obtuse).
Curated OER
Area of Tangram Pieces
Mathematicians calculate the area of a tangram piece without using formulas. They use a geometry journal to record activities during this lesson. They make a set of tangrams and use them to compute area. They use what they discover to...
Hotchalk
Triangle Sum Theorem
Your visual geometry learners will appreciate triangle drawings as they model the triangle sum theorem and algebraically solve to find the missing interior angle in a triangle. Practice problems increase in complexity and vary in their...
Scholastic
Study Jams! Area of Irregular Figures
Painting an irregular figure can be tricky if we don't know the exact area. This interactive presentation reveals that irregular figures can be broken into smaller, simple figures that use the area formulas. Go through two examples,...
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...
Alabama Learning Exchange
Triangle Area: No Height? Use the Sine
No height? No problem! Learners use their knowledge and a little help from GeoGebra to develop the Law of Sines formula. The Law of Sines helps to determine the height of triangles to calculate the area.
Illustrative Mathematics
Equal Area Triangles on the Same Base II
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,...
Flipped Math
Sectors and Segments
It's a piece of pizza! Pupils learn about a sector of a circle as a slice of the circle and determine how to find its area. Scholars continue to find out how to calculate the segment of a circle based on the sector's area. At the end,...
Curated OER
Finding the Area of Polygons
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...
Curated OER
Leveled Problem Solving Areas of Triangles and Trapezoids
In this geometry worksheet, 6th graders calculate the area of triangles and trapezoids using the given formulas. They use the formulas to find measurements of lines that are part of the triangles and trapezoids.
Noyce Foundation
Parallelogram
Parallelograms are pairs of triangles all the way around. Pupils measure to determine the area and perimeter of a parallelogram. They then find the area of the tirangles formed by drawing a diagonal of the parallelogram and compare their...