Views
Downloads
Printable Law of Cosines Quiz Worksheet | Grade 10-12 Math
Paste this activity's link or code into your existing LMS (Google Classroom, Canvas, Teams, Schoology, Moodle, etc.).
Students can open and work on the activity right away, with no student login required.
You'll still be able to track student progress and results from your teacher account.
This Law of Cosines worksheet helps students find missing sides and angles in non-right triangles and decide when the Law of Cosines applies. Students complete a 20-point quiz and four exit tickets, then explain whether an angle is acute or obtuse using the sign of its cosine.
At a Glance
- Grade: 10–12 · Subject: Math
- Standard:
HSG-SRT.D.11— Use the Law of Cosines to find unknown sides and angles in triangles.- Skill Focus: Law of Cosines for SAS and SSS triangles
- Format: 2 pages · 17 problems · Answer key included · PDF
- Best For: Short assessment and exit tickets
- Time: 25–35 minutes
What's Inside
Part A is a 20-point quiz with two SAS side problems, two SSS angle problems, a full solve-the-triangle item, a hiker word problem, and a Law of Sines versus Law of Cosines choice with a written explanation. Part B has four exit tickets (two SSS, two SAS), each with a calculation and an acute-or-obtuse reflection. The 2-page answer key shows every answer, rounded to the nearest tenth.
Skill Progression
- Guided practice: 4 single-step quiz problems (2 SAS, 2 SSS) with rounding and calculator-precision directions at the top.
- Supported practice: 4 exit tickets that pair a calculation with a reflection prompt, so students connect the cosine sign to the angle type.
- Independent practice: a multi-part triangle solution, a word problem, and a law-choice explanation with no prompts.
The sequence follows gradual release: I Do, We Do, You Do.
Standards Alignment
HSG-SRT.D.11 asks students to understand and apply the Law of Sines and the Law of Cosines to find unknown measurements in right and non-right triangles. This worksheet focuses on the Law of Cosines and includes one law-selection item. The standard code can be copied directly into lesson plans, IEP goals, or district curriculum mapping tools.
How to Use It
- After direct instruction: assign Part A as a 20-minute quiz at the end of the unit.
- During or after a lesson: hand out one exit ticket at a time and collect it at the door.
As students work, watch for anyone who forgets to take the inverse cosine or uses degrees incorrectly. Expect 25–35 minutes for the full worksheet.
Who It's For
Grade 10–12 Geometry, Algebra II, and Precalculus students who have already learned the Law of Cosines. Students who need more support can start with the exit tickets alone. Pair it with a Law of Cosines anchor chart or a lesson on choosing between the two laws.
The Law of Cosines Quiz and Exit Tickets worksheet for Grades 10–12 Math addresses HSG-SRT.D.11, which asks students to apply the Law of Cosines to find unknown sides and angles in non-right triangles. The two-page resource contains 17 problems: a 20-point quiz covering SAS side lengths, SSS angle measures, a full triangle solution, a word problem, and a choice between the Law of Sines and the Law of Cosines, followed by four exit tickets. Each exit ticket asks students to judge whether an angle is acute or obtuse from the sign of its cosine. Fisher & Frey (2014) describe exit tickets as a quick check for understanding that shows teachers which students need reteaching before the next lesson. A two-page answer key gives all answers rounded to the nearest tenth, with short written explanations, so teachers can score consistently and spot misconceptions quickly.
