This is an interesting geometry problem. Given the figure, find the area of a triangle that is created by the intersecting lines. The solution requires one to use what he/she knows about coordinate geometry, as well as triangle...

Investigate how similar and congruent figures compare. Learners understand congruent figures have congruent sides and angles, but similar figures only have congruent angles — their sides are proportional. After learning the...

It's all Greek to me. Scholars work a task that Greeks first formulated for an ancient math challenge. Provided with an angle and a point inside the angle, scholars develop conjectures about what is true about the shortest line segment...

After walking in a nearby neighborhood, have your class create this amazing city street pop-up. They study the facades of the buildings they see, focusing on geometric line, shape, and architecture. They then draw, cut, and create a city...

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...

This well organized poster shows a step-by-step algebraic proof and related graphic. Understanding how formulas were derived, connects learners to the idea that the study of mathematics is continuous and cumulative. Learners will...

Learners see application of construction techniques in a short but sophisticated problem. Combining the properties of inscribed triangles with tangent lines and radii makes a nice bridge between units, a way of using...

In this area of a triangle worksheet, students solve 30 problems in which the area of triangles are calculated. There is instruction on the page. This is intended for on-line use but can be done on paper.

Students investigate the theorems of ASA, AAS, AAA and ASA. In this geometry lesson plan, students discuss the theorems of triangles and how it is used to solve for missing sides or angles. They review how two angles are formed by two...

Tenth graders investigate the theorems of ASA, AAS, AAA and ASA. In this geometry lesson, 10th graders discuss the theorems of triangles and how it is used to solve for missing sides or angles. They review how two angles are formed by...

In this geometry worksheet, 10th graders review the vocabulary associated with the special segments of a triangle and the associated points of concurrency and solve problems in which they find the indicated missing angle or...

Properties about triangles are explored in this lesson. Geometers make conjectures about the length of a triangle's sides, the length of the angles in relation to the length of the sides, and the measure of the exterior angles of a...

Tenth graders investigate the theorems of ASA, AAS, AAA and ASA. In this geometry lesson, 10th graders discuss the theorems of triangles and how it is used to solve for missing sides or angles. They review how two angles are formed by...

In this postulates and theorems instructional 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...

Students identify positive and negative angles using the Unit Circle. In this pre-calculus lesson, students identify the different angles on a unit circle using the coordinate plane and the four different quadrants as a guide. They...

In this trigonometric ratios worksheet, students find the missing angle of 20 triangles by using sine, cosine and tangent ratios. Students compute the angle measurement of given ratios for six problems.

In this geometry worksheet, students solve right angle triangles using the Pythagorean Theorem. They calculate the area and sides of triangles and circles. There are 52 questions total.

Have your class review how to identify right angles. Learners identify right angles, and then write the number of angles found in each shape.

In this online math instructional activity, students calculate the angles in a triangle given their measurements. This excellent resource allows the students to check their answers, and to get "hints" should they run into difficulties. A...

For this geometry worksheet, students identify the missing angles of non right triangles using the angle sum theorem. They solve for the unknown using algebra. There are 21 questions.

Students model scenarios using functions and their properties. In this trigonometry instructional activity, students calculate the angles of sine, cosine and tangent. They perform operation using a calculator.

Students identify similar and congruent right triangles. In this geometry lesson, students use trigonometric ratios to identify missing sides and angles of a triangle. They differentiate similar and congruent triangles.

Students calculate the measurements of the inscribed angles of a triangle. For this geometry lesson, students relate the hypotenuse of a right triangle and the diameter of a circle to each other. They calculate the diameter of a circle...

In this geometry skills practice worksheet, students respond to 9 questions that require them to calculate the measurements of the unknown angles.