In this geometry worksheet, students differentiate between similarity and congruence. They find the correct answer using the theorems of similarity and congruence. There are 5 questions with an answer key.

In this geometry worksheet, students find the measures of the side of a triangle. They use the Pythagorean Theorem to find the different parts of a right triangle. There are 10 questions with an answer key.

In this geometry activity, 10th graders apply the circle segment theorems to determine the indicated segment length. The one page activity contains twenty problems. Answers are not provided.    

In this geometry worksheet, 10th graders use the theorems regarding circles and tangents to find the indicated missing segment length.  The one page interactive worksheet contains ten problems.  Answers are included. 

Learners discover how to recognize tangents and how to use their properties. They investigate and use the properties of angles, arcs, chords, tangents, and secants. Students use two tangents and the properties of similar triangles to...

Young scholars use Geometers SketchPad to find the area and perimeter of several shapes. In this geometry lesson, students determine area of rectangles and progress through irregular polygons. None of the referenced worksheets are...

Students use problem solving skills, formal geometry, and The Geometer?s Sketchpad. They model and solve two real-world problems by constructing the in center and circumcenter of triangles.

Students explore the making of circles and concepts related to them in geometry. The project is inquiry based will focus upon students making their own nametags. The construction is ideal for hands on students.

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...

Our teacher told us the formula had one-third, but why? Using manipulatives, classmates try to explain the volume formula for a pyramid. After constructing a cube with six congruent pyramids, pupils use scaling principles from...

Compare and contrast the four types of transformations through constructions! Individuals are expected to construct the each of the different transformations. Although meant for a review, these examples are excellent for initial...

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...

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...

Everyone knows that opposite sides of a parallelogram are congruent, but can you prove it? Challenge pupils to use triangle congruence to prove properties of quadrilaterals. Learners complete formal two-column proofs before moving on to...

Not all triangles are right! Pupils learn to tackle non-right triangles using the Law of Sines and Law of Cosines. After using the two laws, they then apply them to word problems. 

Putting a rectangular object into a circular one—didn't the astronauts on Apollo 13 have to do something like this? Learners first construct the center of a circle using perpendiculars. They then discover how to inscribe a rectangle in a...

How many ways can you create a dilation? Many! Individuals strengthen their understanding of dilations by using various methods to create them. The new technique builds on pupils' understanding of the ratio method. Using the ratio,...

Are pyramids and cones similar in definition to prisms and cylinders? By examining the definitions, pupils determine that pyramids and cones are subsets of general cones. Working in groups, they continue to investigate the relationships...

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.

Pupils explore the concept of triangle inequalities.  In this triangle inequality lesson, students cut spaghetti noodles into given lengths.  Pupils use the noodles to complete a worksheet about triangle inequalities. ...

Students find the different ratios of a right triangle. In this geometry lesson plan, students apply the concept of the Pythagorean theorem as they identify the different angles and parts of a Unit Circle. They find the ratios of sine,...

In this similarity worksheet, students use similar rectangles to find the length of a diagonal. They use symbols and write paragraphs to explain the problem. This one-page worksheet contains one similar problem with 13 related questions.

Learners investigate the Napoleon triangle theory. In this polygon lesson, students  differentiate between the boundary points, interior and lattice point of a polygon. They apply concepts of equilateral triangles to solve...

In this triangles worksheet, students identify the median, altitude, segment, angle bisector, perpendicular bisector and triangle midsegment of triangles.  They find the perimeter of triangles.  This three-page worksheet...