Illustrative Mathematics
Sum and Difference Angle Formulas
Need practice deriving trigonometric angle formulas? With this worksheet, pupils derive the sum and difference formulas for cosine and tangent and the difference formula for sine. Scholars use the sine sum formula and other known...
Illustrative Mathematics
Sum of Angles in a Polygon
How can learners use algebra to solve a geometry problem? Help learners create an equation that shows the relationship between the number of sides of a polygon and the sum of the interior angles. Students are asked to divide the...
Chapman University
A Pythagorean-Style Proof of the Sine Sum-of-Angles Formula
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 also...
Mathed Up!
Angles in Polygons
Show your class that finding angle measures is a regular calculation with a resource that provides 12 problems dealing with the measures of angles in regular polygons. Pupils use formulas for the sum of measures of angles in a polygon to...
Curated OER
Sum and Difference angle formulas
Learners use the sum angle formula for sine to derive the sum and difference formulas for cosine and tangent. The level of difficulty is quite high. Learners must be familiar with trigonometric identities as well as the characteristics...
EngageNY
Addition and Subtraction Formulas 2
Knowing the addition formulas allows for the calculations of double and half formulas. The fourth installment of 16 has the class use the addition formula to develop the double angle trigonometric formulas. Using the double formula,...
Hotchalk
Triangle Sum Theorem
Your visual geometry learners will appreciate triangle drawings as they model the triangle sum theorem and algebraically solve to find the missing interior angle in a triangle. Practice problems increase in complexity and vary in their...
Willow Tree
Interior Angles, Exterior Angles, and Diagonals of Polygons
How does the number of sides of a polygon affect the angle measures? Learners recognize a pattern in finding the total measure of interior and exterior angles and the number of diagonals. They use the patterns to calculate the number of...
Curated OER
Double-Angle and Half-Angle Formulas
In this college level Pre-Calculus worksheet, students use the double-angle and half-angle formulas to evaluate trigonometric expressions and solve trigonometric equations. The six page worksheet contains fifty-six problems. Answers are...
Curated OER
Section 2.5 - Problem Solving (Part B)
Trying to figure out the perimeter of a geometric figure? Here are a few word problems to set up algebraic equations to solve for perimeter. There are also some word problems to set up algebraic equations to solve for angles in a...
Del Mar College
Formulas for Elementary and Intermediate Algebra
Give your scholars the support they need to work with formulas. A reference page offers definitions and picture examples of perimeter, area, surface area, volume, the Pythagorean theorem, a variety of shapes, and more.
Curated OER
Tile Patterns I: Octagons and Squares
This can be used as a critical thinking exercise in congruence or as a teaching tool when first introducing the concept. Four octagons are arranged in such a way that a square is formed in the middle. With this information, geometry...
Virginia Department of Education
Angles in Polygons
Polygons — it's all about the angles. Groups work with dynamic geometry software to find the sum of the measures of the angles of various polygons. After finding the information for several polygons, the groups generate a formula that...
EngageNY
Addition and Subtraction Formulas 1
Show budding mathematicans how to find the sine of pi over 12. The third lesson in a series of 16 introduces the addition and subtraction formulas for trigonometric functions. Class members derive the formulas using the distance formula...
Curated OER
Relationship between Exterior and Remote Interior Angles in a Triangle
In this triangle worksheet set, 9th graders find the relationship between the exterior and remote interior angles in triangles. They determine the formula, and apply it in 15 problems. They use a compass as needed to measure angles.
Curated OER
Around The Stop Sign
Students analyze a drawing of a regular octagon inscribed in a circle to determine angle measures, using knowledge of properties of regular polygons and the sums of angles in various polygons to help solve the problem. They use...
Flipped Math
Unit 3 Review: Parallell and Perpendicular Lines
Learners watch a quick review on the Parallel and Perpendicular Lines unit. The pupils work through ten review problems ranging from identifying types of angles formed by parallel lines and transversals to writing equations of parallel...
Curated OER
Interior and Exterior Angles of Polygons
In this online math worksheet, students find the interior and exterior angles of polygons. This excellent resource allows the students to check their answers, and to get "hints" should they run into difficulties. A terrific teaching tool!
Curated OER
Polygon Sum Conjecture
Young scholars calculate the sum of the angles of a polygon. In this geometry lesson, students use the interior angle formula of polygon based on the number of sides of the polygon. They identify the missing angle using algebra.
Curated OER
Sum of Exterior Angles of Polygons
Have fun calculating angles for different polygons. The class differentiate the relationship between the interior and exterior angles of polygons. They discuss linear pair as it related the polygons and their angles. This is done as they...
Curated OER
Patterns in the Sums of Polygon Angles
Sixth graders discover the patterns of sums of polygon angles. In this math lesson, 6th graders study the properties of geometric shapes to solve problems as they participate in hands-on activities.
Curated OER
Interior Angles of Polygons
In this online math worksheet, students determine the interior angles of polygons given their exterior measurements. This excellent resource allows the students to check their answers, and to get "hints" should they run into...
Curated OER
Patterns in the Sums of Polygon Angles
Sixth graders are introduced to how to calculate the interior angles of polygons. Using a worksheet from a previous lesson, they use those answers to determine the sum of the angles of the pattern blocks. To end the lesson, they tear...
Curated OER
Geometry w/o Figures - Week 7 (Basic Geometry Formulas)
In this basic geometry worksheet, students use basic formulas of geometry to find the area of a polygons, the number of sides of a polygon, and sum of the angles of various polygons. This three-page worksheet contains eight problems.