Helping with Math
Geometry: Areas of Triangles
For this areas of triangles instructional activity, students observe given polygons. They determine the area of triangles, rectangles and compound figures. This one-page instructional activity contains 5 multi-step problems. This...
Curated OER
Coordinate Planes - Area of Triangle
In this online math worksheet, learners 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...
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.
Curated OER
Developing Formulas for Triangles and Quadrilaterals
In this geometry worksheet, 10th graders determine the area of triangles, parallelograms, trapezoids, kites, and rhombuses. The one page worksheet contains eleven problems. Answers are included.
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,...
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 a Triangle
Students solve the area of triangles. For this precalculus lesson, students are given two sides of a triangle and asked to calculate the area. They apply the law of sine and the side-angle-side area formula to solve.
101 Questions
Best Triangle
What makes an equilateral triangle equilateral? It turns out it's much more than just the side lengths! Learners analyze four different triangles to determine the best equilateral triangle. They create a formula that they later use to...
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.
Buffalo State
A Five Day Approach to Using Technology and Manipulatives to Explore Area and Perimeter
Young mathematicians build an understanding of area and perimeter with their own two hands in a series of interactive geometry lessons. Through the use of different math manipulatives, children investigate the properties 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...
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...
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...
Illustrative Mathematics
Same Base and Height, Variation 1
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...
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...
Centre for Innovation in Mamatics Teaching
Areas and Perimeters
Cover some serious area in your geometry curriculum with this collection of worksheets. After first introducing the concept of area using the tiling method, this resource continues on to teach learners how to use...
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...
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.
Curated OER
Six Find the Area of Triangles Given the Vertices Problems
For this area of a triangle worksheet, students calculate the area of six triangles given the coordinate of the vertices. Grids are provided.
Curated OER
Perimeter and Area of Triangles (B)
In this geometry worksheet, students calculate the perimeter and area for each of 4 triangles using the given measurements. They work with measurements that are labeled in centimeters.
Curated OER
Area of Shaded Region (rectangles and triangles)
In this online math learning exercise, students determine the area of shaded regions within rectangles and triangles. This excellent resource allows the students to check their answers, and to get "hints" should they run into...
Curated OER
Areas of Trapezoids, Rhombuses and Kites
Students calculate the area of different polygons. In this geometry lesson plan, students find the area for trapezoids, rhombuses and kites.
Curated OER
Heron's or Hero's Formula for Area of Scalene Triangle
In this Heron's or Hero's formula for area of scalene triangle worksheet, students solve 4 word problems using the formula given for area of a triangle.
Curated OER
Leveled Problem Solving Areas of Triangles and Trapezoids
For 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.