Government of Hong Kong
Areas and Volumes - 2D Shapes
Unfortunately for young mathematicians, the world isn't made entirely of parallelograms, triangles, and trapezoids. After first learning the area formulas for these common shapes, students apply this new knowledge to...
Education Development Center
Finding Triangle Vertices
Where in the world (or at least in the coordinate plane) is the third vertex? Given two coordinate points for the vertices of a triangle, individuals find the location of the third vertex. They read an account of fictional...
Willow Tree
Surface Area of Three-Dimensional Figures
Lateral area and surface area are simple concepts, but calculating them is not as easy! Using formulas, learners calculate lateral area and surface area for the same three-dimensional figures. The resource discusses the formula variables...
Curated OER
Area of Triangle
In this area worksheet, learners read and problem solve the area of 8 triangles. Students show their work on each problem on the worksheet.
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...
Curated OER
Triangle Area by OnlineMathLearning.com
For this online math worksheet, middle schoolers practice finding the area of triangles, given their outside dimensions. When complete, students submit their answers and get instant feedback regarding their accuracy.
Curated OER
Unit Squares and Triangles
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...
Curated OER
The Area of a Triangle
In this area of a triangle instructional activity, students solve 30 problems in which the area of triangles are calculated. There is instruction on the page. This is intended for on-line use but can be done on paper.
Curated OER
Area
Learners solve and complete four various types of problems. First, they show on the diagram why the area of a triangle is given by a formula. Then, pupils find the area of each triangle and parallelogram illustrated, They also circle the...
Flipped Math
Parallelograms and Triangles
Expand area problems to incorporate prior knowledge. Pupils begin by reviewing the formulas for finding the area of parallelograms and triangles. The scholars apply previous learning of trigonometric ratios and the Pythagorean Theorem to...
EngageNY
Real-World Area Problems
Not all structures take the shape of a polygon. The 21st lesson in a series of 29 shows young mathematicians they can create polygons out of composite shapes. Once they deconstruct the structures, they find the area of the composite figure.
Curated OER
Area of Triangle Worksheet
In this area worksheet, students find the area of a triangle given the height and the base. They also find the height or base given the area of the triangle. 
Curated OER
Similar Triangles and Trapezoids, and Circles
High schoolers answer two problems involving area of shaded regions. Learners then answers six questions involving perimeter, area, and circumferences. The remaining two questions involve ratios of similar figures.
EngageNY
Perimeter and Area of Polygonal Regions Defined by Systems of Inequalities
When algebra and geometry get together, good things happen! Given a system of inequalities that create a quadrilateral, learners graph and find vertices. They then use the vertices and Green's Theorem to find the area and perimeter of...
Mathed Up!
Surface Area
Surface area is the sum of the parts. Given the measurements of different prisms, pupils determine their surface areas. Individuals find the area of each surface and figure out the surface area by finding the sum. The video, part of a...
EngageNY
The Volume Formula of a Pyramid and Cone
Our teacher told us the formula had one-third, but why? Using manipulatives, classmates try to explain the volume formula for a pyramid. After constructing a cube with six congruent pyramids, pupils use scaling principles from...
Curated OER
Find the Surface Area of the Triangle
In this geometry instructional activity, students are asked to solve for the surface area of a triangle and a trapezoid. They are fiven the height and base. There are 2 questions with an answer key.
Mathed Up!
Sine and Cosine Rules and Area of Triangles
Learners discover how to find missing sides and angles using trigonometry. Scholars first watch a video covering the Law of Sines and Cosines, as well as the area formula for a triangle. To test their knowledge, they complete a worksheet...
Curated OER
Geometry Practice: Area of Polygons #8
In this area of polygons worksheet, high schoolers solve 7 short answer and multiple choice questions about area.  Students find the area of triangles given base and height, or points in the coordinate plane.
Curated OER
Area of Parallelogram and Triangle
In this geometry instructional activity, 10th graders determine the area of triangles and parallelograms. The one page interactive instructional activity contains ten questions. Answers and hints are included. 
Balanced Assessment
Walkway
Evaluate different aspects of geometry with one task. An assessment activity prompts learners to determine the area of a pathway in the shape of a parallelogram. The Pythagorean Theorem and area formulas for various polygons provide the...
EngageNY
End-of-Module Assessment Task: Grade 7 Mathematics Module 6
Determine the level of understanding within your classes using a summative assessment. As the final lesson in a 29-part module, the goal is to assess the topics addressed during the unit. Concepts range from linear angle relationships,...
Curated OER
Using Trigonometry to Find Area
In this Algebra II/Trigonometry worksheet, students use trigonometry to determine the area of a triangle or a parallelogram.  The one page worksheet contains ten problems.  Answers are not provided. 
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...