In this angular size and similar triangles activity, learners use the properties of similar triangles and the ratios of sides to solve for unknowns in given diagrams.

Seventh graders recognize the characteristics of isosceles triangles. In this isosceles triangle instructional activity, 7th graders use geoboards to create isosceles triangles. Students record results and explain why they have an...

In this isosceles triangle worksheet, young scholars solve 19 multiple choice and short answer problems.  Students use the isosceles triangle theorem to determine unknown angle measures.

Students 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...

Young scholars explore what the Bermuda triangle is and the theories as to why it is so mysterious.  In this mystery lesson students read and discuss the history and the mystery behind the Bermuda Triangle. 

Students use similar triangles to find missing heights.  In this using similar triangles to find missing heights lesson plan, students use proportions to find the heights of missing side lengths.  Students find the height of...

Students use Geometer's Sketchpad to draw triangles and explore the classificaiton of each using the mearsures of interior angles and the lengths of the sides.

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...

In this properties of angles, lines and triangles worksheet, 10th graders solve and complete 28 different problems that include determining the measurement of various figures shown. First, they use the geometric properties and theorems...

Students use similar triangles and a sight tool to find the height and distance between large objects. In this similar triangles lesson plan, students use a constructed sight tool to measure the distance and height of an object using an...

In this area of triangles worksheet, students solve 18 area of triangles problems.  Students find the area of various types of triangles given a graph of the triangle.

In this similar triangles instructional activity, students find the scale factor of 6 sets of similar triangles. Students find the scale factor of two similar triangles given a sketch with measurements. Students use proportions to find a...

In this triangles worksheet, students recognize triangles in a picture. Students find all the triangles in the picture, trace them and color them black.

In this triangles worksheet, students respond to 4 short answer problems. Kids describe side relationships of different types of triangles. Students find the area of a segment formed by a sector.

Students 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. Students read life...

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....

In this right triangles worksheet, 10th graders solve and complete 5 different types of problems. First, they solve each of the right triangles shown and express each answer correct to two decimal places. Then students find the...

For this areas of triangles instructional activity, students observe given polygons. They determine the area of triangles, rectangles and compound figures. This one-page instructional activity contains 5 multi-step problems. This...

Students map magnetic fields of a magnet using a compass and predict where fields cancel each other to create 'Bermuda Triangles'. In this magnetism lesson, students use a compass to map the magnetic field of a magnet. They explain how...

In this proofs worksheet, students construct 1 proof of the law of cosines.  Students construct a right triangle within a circle to  prove the law of cosines.

Sixth graders graph translations (slides) and reflections (flips) on a coordinate plane. They visualize and identify geometric shapes after applying transformations on a coordinate plane. Finally, 6th graders write a paragraph telling...

This amazingly extensive unit covers a wealth of geometric ground, ranging from constructions to angle properties, triangle theorems, rigid transformations, and fundamentals of formal proofs.  Each of the almost-forty lessons...

Students examine the painting "Old Man With A Gold Chain" by Rembrandt. They identify geometric shapes in the painting, measure these shapes and compare the relationships of these measurements.

For any teacher who is planning a field trip to Missouri's Botanical Garden, this instructional activity packet is a must-have! In it, young learners engage in pre-visit activities so they will be prepared to get the most out of their...