Homeschool Math
Homeschool Math: Area of Parallelograms
This instructional activity presents the idea that the area of any right triangle is exactly half of a certain rectangle, and contains varied exercises for learners.
Illustrative Mathematics
Illustrative Mathematics: G Gpe Triangle Perimeters
Students are shown two triangles touching points on a coordinate grid and are asked to answer questions about their perimeters. The purpose of this task is to apply the Pythagorean theorem to calculate distances and areas. Aligns with...
Illustrative Mathematics
Illustrative Mathematics: 6.g Base and Height
The purpose of this task is to help students understand what is meant by a base and its corresponding height in a triangle and to be able to correctly identify all three base-height pairs. Aligns with 6.G.A.1.
Texas Instruments
Texas Instruments: Move Along Little Vertex
In this activity, students use the Geoboard to determine the area of triangles having the same base and same height.
Cuemath
Cuemath: Right Angled Triangle
Explore and learn about the features and properties of a right triangle in this lesson. Includes examples and practice questions.
CK-12 Foundation
Ck 12: Geometry: Perimeter and Area Study Guide
[Free Registration/Login may be required to access all resource tools.] This study guide looks at the definitions and units for perimeter, area, and circumference, and at the perimeter and area of different shapes, including regular...
Illustrative Mathematics
Illustrative Mathematics: 8.g Circle Sandwich
Eighth graders are presented with a drawing of a large square inscribed by a circle which is itself inscribed by a second square. They are asked to find the area of the circle outside the smaller square and compare it to the area of the...
Other
Algebra Lab: Areas and Perimeters of Triangles and Special Quadrilaterals
Learn how to find the areas and perimeters of triangles and special quadrilaterals.
Khan Academy
Khan Academy: Area and Perimeter on the Coordinate Plane
Find the area or perimeter of shapes like triangles, rectangles, parallelograms, and hexagons on the coordinate plane. Students receive immediate feedback and have the opportunity to try questions repeatedly, watch a video or receive hints.
Math Open Reference
Math Open Reference: Triangles
A complete reference guide to types of triangles and triangle perimeter and area. It provides definitions and interactive animated activities that enhance further explanation.
Illustrative Mathematics
Illustrative Mathematics: 8.g Two Triangles' Area
In this task, 8th graders are given the dimensions of two isosceles triangles and are asked to compare their areas. They must draw them and use the Pythagorean Theorem and the triangle area formula to solve the problem. Aligns with 8.G.B.7.
The Math League
The Math League: Area and Perimeter
This tutorial provides a brief introduction about what area is, then gives the formulas for area of a square, rectangle, parallelogram, trapezoid, triangle, and circle. Examples of each formula are provided.
Calculator Soup
Calculator Soup: Isosceles Triangles Calculator
Use this calculator to find the sides, perimeter, area, semiperimeter, and altitude of an isosceles triangle.
Khan Academy
Khan Academy: Area Challenge
Practice solving problems involving triangles, parallelograms, and composite figures. Exercises include decimals, fractions, and word problems. Area of circles is not included. Students receive immediate feedback and have the opportunity...
Khan Academy
Khan Academy: Find Base and Height on a Triangle
Identify the height of a triangle when given the base. Students receive immediate feedback and have the opportunity to try questions repeatedly, watch a video or receive hints.
Khan Academy
Khan Academy: Area & Perimeter on the Coordinate Plane
Find the area or perimeter of shapes like triangles, rectangles, parallelograms, and hexagons on the coordinate plane.
Math Open Reference
Math Open Reference: Perimeter of a Triangle
Learn about the perimeter of a triangle with this helpful reference tool. Provides a detailed definition, an example, and an internet activity that enhances further explanation. Includes links to related topics.
Learning Wave Communications
Learning Wave: Geometry, Section 2
Geometry concepts are briefly discussed at this site, including volume of a cylinder, parallelograms, circles, trapezoids, and triangles. Sample problems and applications are included for practice.
Math Slice
Math Slice: Area & Perimeter: Math Worksheets
This tool allows you to create worksheets of word problems at varying levels of difficulty where students must calculate the area or perimeter of different polygon shapes. You can choose to set up the page using any of these polygon...
CK-12 Foundation
Ck 12: Geometry: Applications of the Pythagorean Theorem
[Free Registration/Login may be required to access all resource tools.] In this lesson students use the Pythagorean Theorem to find perimeter and area. Students examine guided notes, review guided practice, watch instructional videos and...
Calculator Soup
Calculator Soup: Equilateral Triangles Calculator
An equilateral triangle is a special case of a triangle where all 3 sides have equal length and all 3 angles are equal to 60 degrees.
Math Open Reference
Math Open Reference: Polygons
Get the definition and properties of a polygon. Then explore such topics as: 1) types of polygon 2) area 3) Perimeter 4) angles associated with polygons and 5) names of polygons.
Better Lesson
Better Lesson: Remarkable Rectangles
Rectangle is SO MUCH like triangle! Those darned angles--they'll get beginning learners! This is a fun way to practice rectangle!
BBC
Bbc: Bitesize: Maths: 2 D Shapes
Learn about the properties of 2-D shapes: circles, triangles, polygons, and quadrilaterals. Includes information, video, and examples about each, with games and quizzes for reinforcement.