EngageNY
An Area Formula for Triangles
Use a triangle area formula that works when the height is unknown. The eighth installment in a 16-part series on trigonometry revisits the trigonometric triangle area formula that previously was shown to work with the acute triangles....
Curated OER
Area of Triangle Using Trigonometry
In this trigonometry learning exercise, students determine the area of triangles using the trigonometry ratios of sine, cosine, and tangent. This one-page learning exercise contains ten problems.
Mathed Up!
Sine and Cosine Rules and Area of Triangles
Learners discover how to find missing sides and angles using trigonometry. Scholars first watch a video covering the Law of Sines and Cosines, as well as the area formula for a triangle. To test their knowledge, they complete a worksheet...
Curated OER
The Law of Sines
In this law of sines worksheet, students use the law of sines to find the missing measurement in a triangle. They determine the value of angles and the lengths of triangles. Students compute the area of triangles. This four-page...
Curated OER
Law of Sines and Cosines
In this sine and cosine worksheet, students solve given triangles using the law of sines and cosines. They determine the area of triangles. This three-page worksheet contains 12 multi-step problems.
National Council of Teachers of Mathematics
Improving Archimedes' Method
For this Archmides' method instructional activity, students determine the area of a regular n-gon inscribed in a circle. They use sine and cosine functions to solve problems. This three-page instructional activity contains 4...
Curated OER
Law of Sines and Law of Cosines
In this Pre-calculus/Trigonometry activity, students use the laws of sines and cosines to solve triangles. The four page activity contains thirteen problems. Answers are not included.
Curated OER
Trigonometry Worksheet
In this trigonometry worksheet, students use the law of sines to find the length of a missing side of a triangle. They prove trigonometric identity and use Heron's formula to find the area of a triangle. This two-page worksheet...
Curated OER
Trigonometric Triangles
In this trigonometry worksheet, students find the missing angle and sides given the 6 trigonometric values. There are 6 questions with an answer key.
Curated OER
Section 6.1-6.2 Precalculus: Trigonometry
In this trigonometry worksheet, students solve 15 triangle problems. Students use the law of sines and law of cosines to find the missing angles and side lengths of a triangles.
Curated OER
Hunter Fred's Quest for Dinner
Learners solve problems using trigonometric functions, specifically a problem about a tree stand. Pupils try to maximize the distance of hunting sight given certain restrictions. They use the Pythagorean Theorem, sine, cosine, and...
Curated OER
Trigonometric Ratios
In this trigonometric ratios worksheet, learners determine the value of trigonometric ratios. They find the area of triangles, determine the length of one side, and compute the degrees in an angle. This five-page worksheet...
EngageNY
Law of Cosines
Build upon the Pythagorean Theorem with the Law of Cosines. The 10th part of a 16-part series introduces the Law of Cosines. Class members use the the geometric representation of the Pythagorean Theorem to develop a proof of the Law of...
EngageNY
End-of-Module Assessment Task: Pre-Calculus Module 4
Challenge your scholars to show what they know about the Law of Sines, Law of Cosines, and inverses. The six-question assessment is the last in a series of 16. Pupils find the area of triangles and show that the Law of Sines and Law of...
Curated OER
Basic Theorems and Proofs
In this pre-calculus worksheet, 11th graders recall the three forms of the law of cosines and used it to solve problems involving triangles. They also write out the laws of sines and use those to solve problems with angles. There are 15...