+
Lesson Plan
EngageNY

Inscribed Angle Theorem and Its Applications

For Teachers 9th - 10th Standards
Inscribed angles are central to the lesson. Young mathematicians build upon concepts learned in the previous lesson and formalize the Inscribed Angle Theorem relating inscribed and central angles. The lesson then guides learners to prove...
+
Lesson Plan
EngageNY

Unknown Angle Problems with Inscribed Angles in Circles

For Teachers 9th - 10th Standards
We know theorems about circles—now what? Class members prove a theorem, with half the class taking the case where a point is inside the circle and half the class taking the case where a point is outside the circle. The lesson then...
+
Lesson Plan
EngageNY

The Angle Measure of an Arc

For Teachers 9th - 10th Standards
How do you find the measure of an arc? Learners first review relationships between central and inscribed angles. They then investigate the relationship between these angles and their intercepted arcs to extend the Inscribed Angle Theorem...
+
Lesson Plan
EngageNY

Arcs and Chords

For Teachers 9th - 10th Standards
You've investigated relationships between chords, radii, and diameters—now it's time for arcs. Learners investigate relationships between arcs and chords. Learners then prove that congruent chords have congruent arcs, congruent arcs have...
+
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

Unknown Length and Area Problems

For Teachers 9th - 10th Standards
What is an annulus? Pupils first learn about how to create an annulus, then consider how to find the area of such shapes. They then complete a problem set on arc length and areas of sectors.
+
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...
+
Lesson Plan
EngageNY

Equations for Tangent Lines to Circles

For Teachers 9th - 12th Standards
Don't go off on a tangent while writing equations of tangent lines! Scholars determine the equations for tangent lines to circles. They attempt both concrete and abstract examples, such as a tangent line to the unit circle through...
+
Lesson Plan
EngageNY

Cyclic Quadrilaterals

For Teachers 9th - 12th Standards
What does it mean for a quadrilateral to be cyclic? Mathematicians first learn what it means for a quadrilateral to be cyclic. They then investigate angle measures and area in such a quadrilateral.
+
Lesson Plan
EngageNY

Construct an Equilateral Triangle (part 2)

For Teachers 9th - 10th Standards
Triangles, triangles, and more triangles! In this second installment of a 36-part series, your young mathematicians explore two increasingly challenging constructions, requiring them to develop a way to construct three triangles that...
+
Lesson Plan
EngageNY

Copy and Bisect an Angle

For Teachers 9th - 10th Standards
More constructions! For this third installment of a 36-part series, learners watch a YouTube video on creating door trim to see how to bisect an angle. They then investigate how to copy an angle by ordering a given list of steps.
+
Lesson Plan
EngageNY

Construct a Perpendicular Bisector

For Teachers 9th - 10th Standards
How hard can it be to split something in half? Learners investigate how previously learned concepts from angle bisectors can be used to develop ways to construct perpendicular bisectors. The resource also covers constructing a...
+
Lesson Plan
EngageNY

Special Lines in Triangles (part 2)

For Teachers 9th - 10th Standards
Medians, midsegments, altitudes, oh my! Pupils study the properties of the median of a triangle, initially examining a proof utilizing midsegments to determine the length ratio of a median. They then use the information to find missing...
+
Lesson Plan
EngageNY

Congruence Criteria for Triangles—SAS

For Students 9th - 10th Standards
Looking for a different approach to triangle congruence criteria? Employ transformations to determine congruent triangles. Learners list the transformations required to map one triangle to the next. They learn to identify congruence...
+
Lesson Plan
EngageNY

Congruence Criteria for Triangles—AAS and HL

For Students 9th - 10th Standards
How can you prove it? Guide classes through an exploration of two possible triangle congruence criteria: AAS and HL. Learners connect this criteria to those previous learned and also explore criteria that does not work. The lesson...
+
Lesson Plan
EngageNY

Congruence Criteria for Triangles—ASA and SSS

For Students 9th - 10th Standards
How do you know if a pair of triangles are congruent? Use the lesson to help class members become comfortable identifying the congruence criteria. They begin with an exploration of ASA and SSS criteria through transformations and...
+
Lesson Plan
EngageNY

Base Angles of Isosceles Triangles

For Students 9th - 10th Standards
Build confidence in proofs by proving a known property. Pupils explore two approaches to proving base angles of isosceles triangles are congruent: transformations and SAS. They then apply their understanding of the proof to more complex...
+
Lesson Plan
EngageNY

Correspondence and Transformations

For Teachers 9th - 10th Standards
Looking for a strategy to organize the information related to transformations? The materials ask pupils to identify a sequence of rigid transformations, identify corresponding angles and sides, and write a congruence statement. They...
+
Lesson Plan
EngageNY

Characterize Points on a Perpendicular Bisector

For Students 9th - 10th Standards
Learn transformations through constructions! Pupils use perpendicular bisectors to understand the movement of a reflection and rotation. They discover that the perpendicular bisector(s) determine the line of reflection and the...
+
Lesson Plan
EngageNY

Applications of Congruence in Terms of Rigid Motions

For Students 9th - 10th Standards
Corresponding parts, congruent parts, congruent corresponding parts—what does it all mean? The resource challenges pupils to identify corresponding parts for pairs of figures. It uses examples of figures that undergo rigid...
+
Lesson Plan
EngageNY

Construct and Apply a Sequence of Rigid Motions

For Teachers 9th - 12th Standards
Breaking the rules is one thing, proving it is another! Learners expand on their previous understanding of congruence and apply a mathematical definition to transformations. They perform and identify a sequence of transformations and use...
+
Lesson Plan
EngageNY

The Distance from a Point to a Line

For Students 9th - 12th Standards
What is the fastest way to get from point A to line l? A straight perpendicular line! Learners use what they have learned in the previous lessons in this series and develop a formula for finding the shortest distance from...
+
Lesson Plan
Curated OER

Points, Lines, Planes, and Space

For Teachers 9th - 12th
In this points, lines, planes, and space worksheet, students solve word problems dealing with points, lines, planes, and space. Students complete 20 individual problems and 20 group problems.
+
Lesson Plan
EngageNY

How Do Dilations Map Angles?

For Students 9th - 10th Standards
The key to understanding is making connections. Scholars explore angle dilations using properties of parallel lines. At completion, pupils prove that angles of a dilation preserve their original measure. 

Other popular searches