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Curated OER
Word Problems Review Sheet
Word problems can make even expert mathematicians go blank. Practice solving word problems with an extended version of the GUESS method (givens, unknowns, equations, solve, substitute), which adds the steps of drawing a diagram, making...
Charleston School District
Pythagorean Theorem and Converse
You've heard that it is true, but can you prove it? Scholars learn the Pythagorean Theorem through proof. After an overview of proofs of the theorem, learners apply it to prove triangles are right and to problem solve. This is the second...
Charleston School District
The Sum of Angles in a Triangle
An informative lesson contains a brief explanation of how the sum of the angles of a triangle is a line. The lesson continues with determining the missing angle in a triangle, or solving for a variable. Using the sum of the...
Charleston School District
Applications of the Pythagorean Theorem
Use patterns to your advantage! The Pythagorean Theorem allows learners to find missing sides of right triangles. Problems include those with both rational and irrational lengths.
Willow Tree
The Pythagorean Theorem
There isn't a more popular geometry formula than the Pythagorean Theorem! Learners understand the special side relationships in a right triangle. They use the Pythagorean Theorem to find missing sides and to solve problems. They begin...
Charleston School District
The Distance Between Points
Find the shortest distance from A to B using the Pythagorean Theorem! Scholars learn they can find the distance between two points by creating a right triangle using the horizontal and vertical lengths and applying the Pythagorean...
Willow Tree
Surface Area of Three-Dimensional Figures
Lateral area and surface area are simple concepts, but calculating them is not as easy! Using formulas, learners calculate lateral area and surface area for the same three-dimensional figures. The resource discusses the formula variables...
Willow Tree
Midpoint and Distance Formulas
The shortest distance between two points is a straight line. Learners use the Pythagorean Theorem to develop a formula to find that distance. They then find the midpoint using an average formula.
Curated OER
Math Handbook: Trigonometry
You'll be spinning in unit circles once you read through this jumbo-sized resource of everything you need to know about trigonometry. Each page has color-coded examples with explicit directions that detail the problems and...
Willow Tree
Ratios and Proportions with Congruent and Similar Polygons
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...
Geometry Help
Geometry Help: Equilateral Triangles
Explains the basic concept of equilateral triangles with step-by-step instructions and methods for solving specific problems on your own relating to this topic.
Geometry Help
Geometry Help: Triangle Inequalities
Explains the basic concept of triangle inequalities with step-by-step instructions and methods for solving specific problems on your own relating to this topic.
Geometry Help
Geometry Help: Similar Triangles
Explains the basic concept of similar triangles with step-by-step instructions and methods for solving specific problems on your own relating to this topic.
Geometry Help
Geometry Help: Congruent Triangles
Explains the basic concept of congruent triangles with step-by-step instructions and methods for solving specific problems on your own relating to this topic.
Geometry Help
Geometry Help: Triangles
Explains the basic concept of triangles with step-by-step instructions and methods for solving specific problems on your own relating to this topic.
Geometry Help
Geometry Help: Right Triangles
Explains the basic concept of right triangles with step-by-step instructions and methods for solving specific problems on your own relating to this topic.
Geometry Help
Geometry Help: Isosceles Triangles
Explains the basic concept of isosceles triangles with step-by-step instructions and methods for solving specific problems on your own relating to this topic.
Purple Math
Purplemath: Right Triangle Word Problems
Demonstrates how to translate, set up, and solve basic right-triangle word problems.
Purple Math
Purplemath: Determinant Word Problems
Matrix determinants can be used to solve many algebra and geometry word problems. Among them: finding the area of a triangle, finding the area of a parallelogram, and finding the equation of a line between two points. These three...
Purple Math
Purplemath: Basic Trigonometric Ratios: Examples
Demonstrates how to use trig ratios to do simple solving of triangles.
Purple Math
Purplemath: Geometry Word Problems: Introduction
Introduces how to set up and solve simple geometric-figure word problems. Includes advice regarding formulas to memorize.
Geometry Help
Geometry Help: Pythagorean Theorem
Explains the basic concept of the Pythagorean Theorem with step-by-step instructions and methods for solving specific problems on your own relating to this topic.
Geometry Help
Geometry Help: Hinge Theorem
Provides a detailed definition of the Hinge Theorem with step-by-step instructions and methods for solving problems on your own.
Geometry Help
Geometry Help: Squares
Explains the basic concept of a square with step-by-step instructions and methods for solving specific problems on your own relating to this topic.