Lesson Plan
Curated OER

Connecting Formulas Related to Geometric Figures

For Teachers 8th - 12th
Students identify diagrams of quadrilaterals and circles by different names and classify the figures. They name the areas for each diagram and practice solving the formulas for each.
Worksheet
Curated OER

Similar Triangles and Trapezoids, and Circles

For Students 9th - 12th
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.
Lesson Plan
Curated OER

Geometry, Pi, and Ancient Civilizations

For Teachers 8th - 9th
By working together, pairs of students will complete a Pi webquest. Using the internet, they examine the ways people in the Ancient Civilizations of Egypt, Babylonia and Greece used Pi. To end the lesson, they review the concepts of...
Worksheet
Curated OER

Circle Area, Perimeter and Circumference

For Students 5th - 8th
In this geometry skills worksheet, students respond to 7 questions that require them to find the area, perimeter, and circumference of circles.
Lesson Plan
EngageNY

Tangent Segments

For Teachers 9th - 12th Standards
What's so special about tangents? Learners first explore how if a circle is tangent to both rays of an angle, then its center is on the angle bisector. They then complete a set of exercises designed to explore further properties and...
Worksheet
Curated OER

Circles

For Students 9th - 10th
For this geometry worksheet, students solve problems by finding the diameter, radius and chord of a circle. They also solve for the area of the circle. There are 10 questions with an answer key.
Worksheet
Curated OER

Area and Perimeter

For Students 10th
In this area and perimeter worksheet, 10th graders solve and complete 18 various types of geometry problems. First, they find the area of a figure shown with consecutive sides perpendicular. Then, students find the area and perimeter of...
Worksheet
Curated OER

Tangent Lines

For Students 10th
In this tangent lines instructional activity, 10th graders solve and complete 13 various types of problems. First, they solve the right triangles for the variables shown. Then, students name a radius, a diameter, a tangent, a secant, a...
Lesson Plan
Curated OER

Inscribing a Circle in a Triangle

For Teachers 9th - 12th Standards
Pupils investigate inscribing a circle in a triangle. They use Cabri Jr. to draw a triangle, locate the incenter, and use the distance from the incenter to a side of the triangle to inscribe a circle. The dynamic nature of the geometry...
Lesson Plan
Curated OER

3.14159265

For Teachers 9th - 12th
Students discover the value of Pi.  In this value of Pi lesson, students measure the circumference and diameter of various circles on their graphing calculator.  Students find the ratio of the circumference to the diameter and...
Worksheet
Curated OER

Geometry Concepts and Applications

For Students 10th
In this concepts and applications review worksheet, 10th graders solve and complete 40 various types of multiple choice problems. First, they write the equation of a vertical line passing through a point. Then, students find the...
Interactive
Curated OER

Ten Multiple-Choice Circle Problems

For Students 9th - 10th
In this circle worksheet, students solve ten multiple-choice questions concerned with the area, radius, diameter, and circumference of a circle.  The solutions are provided by clicking on the "show answers" button on the bottom of...
Interactive
Curated OER

Probability and Geometry Problems

For Students 9th - 12th
In this online math instructional activity, high schoolers consider a variety of scenarios which include elements of geometry and probability. This excellent resource allows the students to check their answers, and to get "hints" should...
Worksheet
Curated OER

Find Radius/Diameter

For Students 2nd - 10th
In this geometry worksheet, students calculate the radius and the diameter of the five given circles. There is an answer key included.
Lesson Plan
Curated OER

Arc Length Lesson

For Teachers 9th - 11th
Students find the length of the arc of a circle. In this geometry lesson, students calculate the length of an arc and find the measure of the central angle given the length of the arc. They convert between linear and angular speed. They...
Worksheet
Curated OER

Chords of Circle

For Students 10th
In this geometry worksheet, 10th graders solve problems using parallel chords, perpendicular bisectors and chords that are equal distance from the center.
Lesson Plan
EngageNY

Arc Length and Areas of Sectors

For Teachers 9th - 10th Standards
How do you find arc lengths and areas of sectors of circles? Young mathematicians investigate the relationship between the radius, central angle, and length of intercepted arc. They then learn how to determine the area of sectors of...
Lesson Plan
EngageNY

Proving the Area of a Disk

For Teachers 9th - 10th Standards
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...
Lesson Plan
Curated OER

Tangents to a Circle

For Teachers 9th - 10th
Young scholars construct tangent lines. In this geometry instructional activity, students identify the point of tangency, secant and tangent lines. They graph the lines on the Ti and make observations.
Interactive
Curated OER

Geometry Worksheets - Volume of Cylinders

For Students 9th - 12th
In this online math worksheet, students determine the volume of cylinders given their dimensions. This excellent resource allows the students to check their answers, and to get "hints" should they run into difficulties. A terrific...
Lesson Plan
Curated OER

Circles and Pi

For Teachers 9th - 11th
Students identify the relationship between the radius and Pi. In this geometry lesson plan, students calculate the circumference and area of a circle. They create visuals to help them see how the circumference relates to Pi.
Interactive
Curated OER

Circles

For Students 10th
In this geometry activity, 10th graders determine the circumference and area of a circle given either the diameter or the radius. The one page interactive activity contains ten questions. Answers and hints are included. 
Lesson Plan
Curated OER

Unit Circle and Triangle

For Teachers 9th - 11th
Students apply the Unit Circle to solve ratios of triangles. For this geometry lesson, students derive the different ratios of a triangle using the Pythagorean Theorem. They find the angles of a unit circle using a right triangle.
Worksheet
Curated OER

Tangents, Secants, and Chords

For Students 10th
In this tangents, secants and chords learning exercise, 10th graders identify and solve 48 different problems that include using 3 different theorems for defining circles. First, they determine the area of each circle with C as the...