How do dilated line segments relate? Lead the class in an activity to determine the relationship between line segments and their dilated images. In the fourth section in a unit of 16, pupils discover the dilated line...

In this geometry worksheet, 10th graders complete an indirect proof and order the sides or angles of a triangle. Also, students determine if a triangle can have sides with the given lengths. The two page worksheet contains twelve...

Middle schoolers construct a three-dimensional model of a city using both similar and congruent figures and geometric transformations. City must have at least ten buildings with each building labeled and may be constructed out of paper...

Students identify the measure of missing exterior angles. In this geometry lesson,students define and apply the exterior angle theorem to solve problems. They use Cabri software to create different angles and make investigations.

Students identify and use the similarity theorem. In this geometry lesson, students differentiate between congruent and similar triangles. They solve problems using the computer modifying shapes by dragging.

Students investigate Menelaus Theorem. In this geometry lesson, students calculate the area of polygons. They differentiate between boundaries point, interior points and area of lattice points.

Learners prove and use Ceva's Theorem to solve problems. In this geometry lesson, students analyze polygons for patterns and calculate the area of each shape. They relate polygons to the real world.

Students investigate Pick's theorem by completing a lab. In this geometry lesson, students construct polygons using cabri software. They calculate the area of polygons and identify the vertices of each shape.

Students identify different parts of a prism and polyhedra. For this geometry lesson, students identify the number of faces, edges and sides of polygons. They solve problems by recognizing patterns.

In this triangle inequality theorem worksheet, students determine the lengths of the sides of triangles and identify the measure of angles. This one-page worksheet contains ten triangle theorem problems.

In this postulates and theorems activity, students explore a concept map containing information about angles and sides, alternate interior angles, and diagonals of a parallelogram.  They use the concept map to prove theorems dealing...

Tenth graders investigate the early history of geometry. In this geometry instructional activity, 10th graders investigate translations, rotations, and reflections. They also solve problems with line of symmetry and rotational symmetry...

Students use the inequality theorem to solve triangles and their properties. In this geometry activity, students are given spaghetti of different lengths and asked to create triangles. They conclude the necessary length needed to make a...

You know the Inscribed Angle Theorem and you know about tangent lines; now let's consider them together! Learners first explore angle measures when one of the rays of the angle is a tangent to a circle. They then apply their...

Trace the links between a variety of math concepts in this far-reaching unit. Ideas that seem very different on the outset (like the distance formula and rigid transformations) come together in very natural and logical ways. This...

Lead the class in a Greek history lesson with a geometric twist. Pupils relate a short video about geometric properties to modern-day methods of solving for unknown angles. They discuss parallel line theorems and complete...

In this similarity activity, students solve and complete 7 different problems that include determining various dimensions of mirrors shown. First, they find the length of the diagonal of the large mirror in the diagram. Then, students...

Is that drawn to scale? Capture the artistry of geometry using the ratio method to create dilations. Mathematicians use a center and ratio to create a scaled drawing. They then use a ruler and protractor to verify measurements. 

Inscribing a square in a circle brings up a number of interesting geometry topics including triangle congruence and how to prove a quadrilateral is a square. This activity is followed up by finding the area of the square and determining...

The problem seems simple: find the area of the equilateral triangle whose sides are each length 1. In fact, this same problem is solved in 8th grade, addressing a different Common Core standard, using the formula for area of a triangle...

Don't circle around the topic, but get right to the center with tons of practice regarding circles in geometry. The note-incorporated activity provides guided practice through many topics such as central angles, inscribed polygons...

In this geometry worksheet, 10th graders determine if a polygon is convex or concave and apply the polygon Angle sum theorem and the polygon exterior angle sum theorem to determine the measures of interior and exterior angles of a...

Students identify properties of triangles. In this geometry lesson, students create triangles using three different segments. They make conjectures and predictions.

Students study relationships between angles, side lengths, perimeters, areas and volumes of similar objects. In this lesson students also create and critique inductive and deductive arguments concerning congruency, similarity and the...