EngageNY
Cyclic Quadrilaterals
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.
Inside Mathematics
Circles in Triangles
Challenge the class with inscribed circles in triangles. The assessment task requests class members use their knowledge of circles and right triangles to prove two triangles are congruent. They go on to utilize their knowledge of...
Curated OER
Sort Triangles and Quadrilaterals
In this triangle/quadrilateral worksheet, students solve 6 problems that ask questions about lengths, parallel line and angles of quadrilaterals and triangles.
Curated OER
Symmetry Using Polygons
Working on symmetry in your class? If so, this learning exercise might be for you. Learners observe different triangles and quadrilaterals, determine which are symmetrical, draw in the lines of symmetry, and color the symmetrical shapes....
Curated OER
Exploring Characteristics of Triangles
Students draw triangles and explore the classification of each using the measures of interior angles and lengths of sides. They investigate the sum of the interior angles of various triangles and conjecture and prove the theorem: The...
Curated OER
Symmetries of a Quadrilateral I
Learners examine the properties of quadrilaterals from the point of view of rigid motion. Different types of quadrilaterals are characterized by their symmetries, so learners explore the symmetries of a described quadrilateral to...
Curated OER
Triangles
Students identify triangles in the real world and construct their own triangle using drinking straws. They explore abstract triangles and find additional geometric shapes such as trapezoids. Students discuss similar shapes and examine...
EngageNY
Properties of Parallelograms
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...
Curated OER
Using Triangles To Make Shapes
In this using triangles worksheet, students create quadrilaterals and hexagons. In this problem solving worksheet, students draw as many quadrilaterals and hexagons as possible.
Curated OER
Area of Quadrilaterals
In this area of quadrilaterals worksheet, 10th graders solve and complete 5 various types of problems. First, they solve each of the triangles shown and find the area of each triangle. Then, students prove that the sum of the squares of...
Curated OER
Finding Areas of Triangles, Rectangles, and Circles
Students find the areas of geometric shapes. In this geometry lesson plan students find and measure the sides, perimeters, and areas of quadrilaterals, triangles, and circles. Students relate the measures to the others by using formulas.
Curated OER
Midsegments of Quadrilaterals
High schoolers explore the concept of quadrilaterals as they find the midsegments of quadrilaterals using Cabri Jr. on a graphing calculator. They find midpoints, slopes, angles, and distances of lines and angles.
Curated OER
Quadrilateral Attributes
Students classify quadrilaterals. In this quadrilateral lesson plan, students identify the characteristics of quadrilaterals. They write their findings in a journal. Students use geoboards to create quadrilaterals from given descriptions.
Raytheon
Understanding Triangles
In this understanding triangles worksheet, students read 6 pages of examples and explanations about identifying triangles, determining length of sides and degrees of angles, including the hypotenuse, then answer 28 questions, answers...
Curated OER
Right Triangles
For this right triangles worksheet, 10th graders solve 10 different problems that include various right triangles. First, they find the value of a base given its hypotenuse. Then, students determine an angle given the perimeter and...
Curated OER
Investigation - Square Numbers and Triangle Numbers
Fifth graders investigate growth patterns using blocks. In this square and triangle numbers lesson plan, 5th graders predict sizes of larger triangles and squares based on numerical patterns they observed while building.
Curated OER
Area of Triangles and Parallelograms
In this area worksheet, students find the area of 21 triangles and parallelograms. Students find the area of each triangle and parallelogram given a sketch and measurements of the figure.
Curated OER
Right Triangles
In this right triangles worksheet, 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 triangle....
Curated OER
Triangle Island
Learners calculate the altitude of triangles. In the web based lesson, students explore the interior distance from a given point in a polygon to its side. They compute the sum of these lengths. Learners read life application problems...
Curated OER
Does the Area of the Quadrilateral Change?
Students study area and quadrilaterals. In this multiplication and area lesson, students use Polystrip models to change rectangles to form different parallelograms. Students find the area of the models use a Geometer Sketchpad to find...
Alabama Learning Exchange
Polygons-Changing Area Versus Changing Perimeter
Investigate the area and perimeter of polygons in this geometry lesson. Young geometers use grid paper to draw a quadrilateral and calculate its area and perimeter. They also read The Greedy Triangle to identify the changing shape of...
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;...
Geometry Accelerated
Coordinate Geometry Additional Practice
Your learners get extra practice using coordinates in calculating mid points, finding end points, deciding if points are collinear, calculations using slope concepts, writing linear equations, using triangles and quadrilaterals, and...
Curated OER
Parallelograms and Triangles
In this parallelogram and triangle worksheet, students answer 10 word problems regarding the area and perimeter of triangles and the area of parallelograms.