Texas Instruments
Drawing a Line Tangent to a Circle
Explore lines tangent to a circle. For this math lesson, learners manipulate circles and lines on a TI calculator. They draw a circle and analyze perpendicular lines intersecting the circle in only one place. This activity works...
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...
Curated OER
Area of Circle Worksheets
In this geometry worksheet, 10th graders calculate the area of circle give either the radius or the diameter. The one page interactive worksheet contains ten questions. Answers and hints are included.
Curated OER
Circle Formulas
Tenth graders apply various circle formulas to determine radii, diameter, circumference, area, arc length, and sector area. The two page worksheet contains twenty-five problems. Answers are not provided.
Virginia Department of Education
Exploring 3-D Geometry
Take young mathematicians on an exploration of the world of 3-D geometry with this seven-lesson unit. After first defining the terms perimeter, area, and volume and how they apply to the real world, students continue on...
Curated OER
The Area of a Circle
Eighth graders find the circumference and diameter of several lids, show the relationship of the two measurements and derive the formula for finding the area of a circle. In this area of a circle lesson plan, 8th graders find...
Curated OER
ExplorA-Pond: 6th Grade Area and Random Number Tables
Sixth graders estimate surface area of a pond using a random number table.
EngageNY
Proving the Area of a Disk
Using a similar process from the first lesson in the series of finding area approximations, a measurement resource develops the proof of the area of a circle. The problem set contains a derivation of the proof of the circumference...
Mathematics Vision Project
Module 5: Circles A Geometric Perspective
Circles, circles, everywhere! Pupils learn all about circles, central angles, inscribed angles, circle theorems, arc length, area of sectors, and radian measure using a set of 12 lessons. They then discover volume formulas through...
EngageNY
Properties of Area
What properties does area possess? Solidify the area properties that pupils learned in previous years. Groups investigate the five properties using four problems, which then provide the basis for a class discussion.
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
Principles of Square Roots Lesson Plan
Middle and high schoolers investigate all the different places in math that square root is present. In this geometry instructional activity, pupils discuss square roots as it relates to a right triangle and construction. They go over...
Curated OER
Area and Perimeter of Regular Polygons - An Extension
Pupils explore the relationship between area and perimeter of polygons.They measure the area and perimeter of regular polygons inscribed in a circle. Learners then discuss how as the number of sides of a regular polygon increase, the...
Curated OER
Lesson 9-3 Practice B: Composite Figures
In this composite figures worksheet, students solve 11 short answer problems. Students find the area of figures composed of various polygons. Students find the area of each figure given a sketch of the figure with various measurements...
Curated OER
Circle Problems - Radius, Diameter, Circumference and Area
In this online math instructional activity, students determine the radius, circumference, diameter and area of circles. This excellent resource allows the students to check their answers, and to get "hints" should they run into...
Mathematics Assessment Project
Calculating Arcs and Areas of Sectors of Circles
Going around in circles trying to find a resource on sectors of circles? Here is an activity where pupils first complete an assessment task to determine the areas and perimeters of sectors of circles. They then participate in an...
Willow Tree
Area of Common Geometric Figures
Scholars can use area formulas, but can they apply what they know about area? The lesson challenges learners to think logically while practicing finding area of shapes such as rectangles, circles, parallelograms, triangles, and other...
Mathematics Assessment Project
Solving Problems with Circles and Triangles
After completing a task involving examining the ratio of areas of triangles and circles in a given figure, scholars examine sample responses to identify other strategies they could use to solve the problem.
Illustrative Mathematics
Representing Half of a Circle
Geometric shapes make great visual models for introducing young mathematicians to the concept of fractions. Looking at a series of four circles, young scholars are asked to determine whether or not one half of each circle is shaded. To...
Virginia Department of Education
Surface Area and Volume of a Cylinder
Surface area or volume? Pupils first review the difference between surface area and volume. They then use a two-dimensional net that helps them develop formulas for the surface area and volume of cylinders.
Balanced Assessment
Triangle in Circle
Even kindergartners can draw triangles in circles, but the assessment task requires a bit more geometric knowledge. Scholars investigate triangles that have a diameter of a circle as one of its sides. They must consider triangles that...
Mascil Project
Circular Pave-Stones Backyard
Pack the lesson into your plans. Young mathematicians learn about packing and optimization with the context of circular paving stones. They use coins to model the paving stones, and then apply knowledge of circles and polygons to...
Curated OER
Perimeter and Area
In this perimeter and area worksheet, 9th graders solve 17 various types of problems, mostly word problems related to determining the area or perimeter of a geometric shape. They also determine the area and perimeter of shaded portions...
101 Questions
Apple Mothership
Explore Apple's spaceship office building. Built in the shape of a circle, the office building offers a unique floor plan challenge. Young scholars use the dimensions of the building to estimate the square footage for each employee.