Geometry Accelerated
Accelerated Geometry Review Sheet
Your geometry learners use their knowledge of various geometric concepts to write proofs. Starting with givens containing parallel line segments with transversals and triangles and quadrilaterals, and the mid-point and distance formulas;...
Mathematics Vision Project
Geometric Figures
Logical thinking is at the forefront of this jam-packed lesson, with young mathematicians not only investigating geometric concepts but also how they "know what they know". Through each activity and worksheet, learners wrestle with...
Curated OER
Reflections and Equilateral Triangles II
Given the lines of symmetry in an equilateral triangle, your learners find where the pre-image vertices are mapped onto the new image. They explore the properties of equilateral triangles, the impact of reflections, and the idea that the...
Curated OER
Reflections and Equilateral Triangles
Your learners collaboratively find the lines of symmetry in an equilateral triangle using rigid transformations and symmetry. Through congruence proofs they show that they understand congruence in terms of rigid motions as they prove...
Curated OER
Is This a Rectangle?
How do you show that something is a rectangle? This activity starts with four coordinate points and asks young geometers to explain whether they create a rectangle. Knowledge from both geometry and algebra come into play here, as well...
Curated OER
Connecting Algebra and Geometry Through Coordinates
This unit on connecting algebra and geometry covers a number of topics including worksheets on the distance formula, finding the perimeter and area of polynomials, the slope formula, parallel and perpendicular lines, parallelograms,...
Illustrative Mathematics
Midpoints of the Sides of a Paralellogram
This task asks learners to prove that the segment joining the midpoints of two sides of a parallelogram is both congruent and parallel to an adjacent side of the parallelogram. The activity would be good to use in a discussion about how...
Illustrative Mathematics
Is This a Parallelogram?
If both pairs of opposite sides of a quadrilateral are congruent, is the quadrilateral a parallelogram? This task asks learners to determine the answer and to support their answer with a proof. The resource includes a commentary for...
Curated OER
Creating Parallelogram
Learning how to define vocabulary words related to solving parallelograms will assist your learners in identifying different parallelograms. They use the navigator to view different shapes created by moving the parallelogram around.
Curated OER
Properties of Special Quadrilaterals
Teach your mathematicians how to identify the properties of quadrilaterals. In this geometry lesson, high schoolers solve for missing angles and sides of a special quadrilateral. They use the TI to move the sides around and create...
Key Curriculum Press
Properties of Special Parallelograms
Rhombuses, rectangles and squares are have special properties. In this lesson plan, young geometers investigate and make conjectures about diagonals, angles, and parallel lines of parallelograms.
Alabama Learning Exchange
Trapezoids: What's Equal or Right About Them?
Pupils explore the concept of trapezoids. In this trapezoids instructional activity, young scholars identify legs and bases of a trapezoid. Pupils discuss the similarities and differences between isosceles trapezoids and right...
Wolfram Research
Wolfram Math World: Geometry
This site provides an understanding of the many types of geometry.
National Council of Teachers of Mathematics
The Math Forum: Ask Dr. Math: Contrapositive, Converse, Inverse
The inverse, converse and contrapositive are defined as Dr. Math answers a question to prove the validity of such statements for a specific problem. The Dr. explains the thinking process for the proof well.
Maths Challenge
Maths challenge.net: Perpendicular Construction
This is a "three star" geometry problem where prior math problem skills and proof experience is recommended to solve this "Perpendicular Construction" problem.
Maths Challenge
Maths challenge.net: Leaning Ladders
Use your right triangle solving skills to solve this ladders in a hole problem.
Maths Challenge
Maths challenge.net: Right Triangle Equal Parts
A geometry proof problem involving a right triangle and finding angles of equal measure.
Maths Challenge
Maths challenge.net: Shaded Triangle
A great geometry problem of area, encorperating many learned skills.
Maths Challenge
Maths challenge.net: Equal Angles
A geometric proof. Prove two angles in this model are equal in measure.
Maths Challenge
Maths challenge.net: Inscribed Rectangle
This is a proof problem, considered a "three star" geometry problem requiring knowledge of proofs and properties of circles to solve this equal area of inscribed polygons problem.
Maths Challenge
Maths challenge.net: Three Circles
This is a proof problem, considered a "three star" geometry problem requiring knowledge of proofs and properties of circles.
Maths Challenge
Maths challenge.net: Maximum Square
A challenging proof like geometry of finding the square inscribed in a triangle.
Maths Challenge
Maths challenge.net: Isosceles Trapezium
This is a "three star" geometry problem where prior knowledge of problem solving and thinking through proofs is recommended to solve this trapezoid inscribed in a semicircle problem.
Maths Challenge
Maths challenge.net: Right Angle Reasoning
A geometry problem for students to use their mathematical reasoning skills to explain a right triangle property.