CK-12 Foundation
Length of an Arc: Pi Hour
What time is it when the arc length is pi? An interactive displays the measure of the angle created between the hour and minute hand of a clock. Pupils can set the clock to different hours and calculate the arc length based upon the radius.
Radford University
Discover Radians!
No need for radians to be mysterious. Scholars use a cardboard cut-out of a unit circle and measure the radius and circumference using a piece of string. They consider the number of radii needed to cover the entire circumference and use...
Flipped Math
Chords and Arcs
Congruence breeds congruence. Pupils learn three more circle theorems dealing with congruent chords and arcs. Learners use the theorems to find the measures of chords and arcs in circles by applying previously learned concepts in the...
Curated OER
Angles and Arcs
Students discuss the sum of central angles and use string to create them on circles. They find the measure and length of both minor and major arcs.
Students give examples of concentric, similar, and congruent circles and congruent arcs.
Curated OER
Polygons
In this polygons worksheet, 10th graders solve 10 different problems that include determining various interior angles in polygons. First, they determine the number of sides a polygon has with a given measure for each angle. Then,...
Curated OER
Interior Angles of Regular Polygons
Students investigate the interior angles of a triangle. In this geometry lesson, students create the formula to calculate the angles inside a triangle. They observe the total sum of a triangles angle on the navigator.
Curated OER
Positive and Negative Angles and Arcs
To better understand that the intersection point of two lines lies inside a circle, learners use their keen measurement skills. They discuss arcs, rays, tangent lines, and reflex angles. Then, they put their skills to work as they...
Inside Mathematics
Hopewell Geometry
The Hopewell people of the central Ohio Valley used right triangles in the construction of earthworks. Pupils use the Pythagorean Theorem to determine missing dimensions of right triangles used by the Hopewell people. The assessment task...
Curated OER
7th Grade Mathematics Booklet
In this 7th grade mathematics compilation instructional activity, 7th graders solve and complete 40 various types of mathematics problems. They determine the measure of various angles and the side-lengths in integers of a square....
Curated OER
Inscribed Angles
Students analyze inscribed angles and intercepted arcs and explore the relationships between the two. They investigate the properties of angles, arcs, chords, tangents, and secants to solve problems involving circles.
Illustrative Mathematics
Seven Circles III
A basic set-up leads to a surprisingly complex analysis in this variation on the question of surrounding a central circle with a ring of touching circles. Useful for putting trigonometric functions in a physical context, as well as...
Curated OER
Arc Length Lesson
Learners 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...
Curated OER
Arc Length and Sectors
Find the length of an arc. Students relate central angles to the area and length of a sector and graph circles on the TI to make predictions.
Curated OER
Electric Hoist Problem
Students convert angle measures between degrees and radians. They are given a copy of the task sheet with a graphic to help describe the situation. Pupils review the angle and arc relationship in a circle related to length of the...
Curated OER
Polygons
For this polygons worksheet, 10th graders solve 10 different problems that include various types of polygons. First, they determine the number of sides that a polygon has if the exterior angle is a certain degree. Then, students...
Curated OER
Trapezoids and Kites Multiple Choice
In this trapezoids worksheet, high schoolers solve 6 multiple choice problems. Students find the lengths of the bases of a trapezoid given a ratio and median length. High schoolers find unknown angle measures of kites and trapezoids...
Curated OER
Measurement Investigations 2
Students complete a number of practical measuring investigations, with an emphasis on accuracy of measuring and communication of their findings. They examine how to measure by first becoming aware of the physical attributes of objects...
Curated OER
Measurement Investigations 1
Fifth graders find perimeters, areas, and volumes of everyday objects and state the precision. They work in small groups in order to take measurements, perform calculations, and write a group report about the investigation.
EngageNY
The Angle-Angle (AA) Criterion for Two Triangles to Be Similar
What do you need to prove triangles are similar? Learners answer this question through a construction exploration. Once they establish the criteria, they use the congruence and proportionality properties of similar objects to find...
EngageNY
Geometry Module 5: Mid-Module Assessment
How can you formally assess understanding of circle concepts? Pupils take a mid-module assessment containing five questions, each with multiple parts.
Curated OER
Trapezoids
In this trapezoids worksheet, 10th graders solve 5 different problems related to trapezoids and applying the appropriate theorem. First, they define a trapezoid, including its bases, legs, and base angles. Then, students use the...
Curated OER
Trapezoids
In this trapezoids worksheet, 10th graders solve 10 different types of problems related to measuring trapezoids. First, they identify the isosceles trapezoid on the sheet with the bases MA and TH. Then, students use the given information...
Curated OER
Thumb Measurement
Learners practice measuring using the metric system and millimeters. They measure their thumbs and record their findings. Students record the findings of their classmates and find the average or mean for the two groups.
Curated OER
Right Triangles
In this right triangles learning exercise, 10th graders solve and complete 14 various types of problems. First, they find the perimeter of the isosceles trapezoid shown. Then, students find the measures of each marked side of a right...