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PreCal - Laws of Sine & Cosine Practice - Printable Mathematics Worksheets - Wayground

PreCal - Laws of Sine & Cosine Practice

15 questions

11th - 11th Grade

Mathematics

PreCal - Laws of Sine & Cosine Practice is a free printable Grade 11 mathematics worksheet that helps students choose and apply the Law of Sines and Law of Cosines in non-right-triangle problems. Across 15 items, students identify the appropriate law, find missing angles and side lengths, solve real-world distance situations, and determine whether an SSA setup produces zero, one, or two triangles. The worksheet also includes fill-in-the-blank problems requiring answers rounded to the nearest tenth with units, a dropdown item for solving multiple parts of a triangle, and area problems using triangle measurements. Students apply their reasoning to find a largest angle, calculate area, and complete an oblique-triangle solution rather than simply recalling formulas. It is suitable for guided practice, independent review, or assessment, and includes a complete answer key for efficient checking.

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Worksheets

PreCal - Laws of Sine & Cosine Practice

Total questions: 15

Name
Class
Date
1.
Which Law would you use?
a)
Law of Sines
b)
Law of Cosines
c)
Law of the Jungle
d)
Law of Gravity
2.
Which Law would you use?
a)
Law of Sines
b)
Law of Cosines
c)
Law of the Jungle
d)
Law of Gravity
3.
Which Law would you use?
a)
Law of Sines
b)
Law of Cosines
c)
Law of the Jungle
d)
Law of Gravity
4.
What would be used to find the distance across the lake?
a)
Quadratic Formula
b)
Law of Cosines
c)
Law of Sines
d)
Trigonometric Ratios
5.
What would be used to find the distance from the Ranger's Tower to the fire?
a)
Quadratic Formula
b)
Law of Cosines
c)
Law of Sines
d)
Trigonometric Ratios
6.
What is the measure of angle A?
a)
50 degrees
b)
60 degrees
c)
78 degrees
d)
74 degrees
7.
What is the length of side x?
a)
130 cm
b)
112 cm
c)
150 cm
d)
105 cm
8.

Jack is flying his kite.  He runs 100 feet away from his house and lets out 75 feet of string.  The angle of elevation from the ground to the kite is 65 degrees.  How far away is the kite from the house?

*Type your answer to the nearest TENTH

*Don't forget your UNITS!!

(a)  

9.

Amanda and Jamie are standing 25 feet apart and spot a bird in the sky between them.  The angle of elevation from Amanda to the bird is 55, and from Jamie to the bird is 63.  How far away is the bird from Amanda?

*Type your answer to the nearest TENTH

*Don't forget your UNITS!

(a)  

10.
In triangle ABC, a = 3, b = 5, c = 7.  What is the measure of the largest angle?
a)
22
b)
38
c)
60
d)
120
11.

In triangle ABC, m<A = 120, b = 10, and c =18.  What is the area of triangle ABC to the nearest square INCH?

*whole number!

(no units necessary)

(a)  

12.
Will this make 1 triangle? 2 triangles? or no triangles?
A= 37°, a=8, b=14
a)
1 Trianlge
b)
2 Triangles
c)
No Triangles
13.
Will this make 1 triangle? 2 Triangles? or No Triangles?
B= 70°, b=85, c=88
a)
1 Triangle
b)
2 Triangles
c)
No Triangles
14.

Solve the Triangle B= 85°, C= 47°, and a=19 Find A, b, and c

Answer: A =​ (a)  

b = ​ (b)  

c = ​ (c)  

Choose from the below words

48°48\degree  

25.525.5  

18.718.7  

39°39\degree  

90°90\degree  

1414  

23.623.6  

23.423.4  

90°90\degree  

32°32\degree  

15.
Find Area of DEF
a)
9.5
b)
119.5
c)
59.8
d)
5.4
Answer Key

PreCal - Laws of Sine & Cosine Practice

Total questions: 15

1.
b) Law of Cosines
2.
b) Law of Cosines
3.
a) Law of Sines
4.
b) Law of Cosines
5.
c) Law of Sines
6.
c) 78 degrees
7.
d) 105 cm
8.
96.4 feet, 96.4 ft, 96.4ft, 96.4feet
9.
25.2 feet, 25.2 ft
10.
d) 120
11.
78, 78 square inches, 78 in²
12.
c) No Triangles
13.
b) 2 Triangles
14.

48°48\degree  

,

25.525.5  

,

18.718.7  

15.
c) 59.8

FAQs

What does this Laws of Sines and Cosines worksheet cover?

This Grade 11 worksheet uses 11 multiple-choice questions, 3 fill-in-the-blank problems, and 1 dropdown item to practice selecting and applying the Law of Sines or Law of Cosines. Students solve for missing sides and angles, analyze the ambiguous SSA case for zero or two triangles, complete an oblique-triangle solution, and calculate triangle area, including applied distance problems that require rounding and units.

How can I use this worksheet to teach students when to use the Law of Sines or Law of Cosines?

Begin by reviewing which known side-angle arrangements support the Law of Sines and which information supports the Law of Cosines, then use the worksheet’s initial “Which Law would you use?” items as a sorting discussion. After students justify their choices, have them work through the distance, missing-side, and missing-angle problems and explain how the given measurements led to each law. Finish with the SSA items to introduce why one setup can produce zero, one, or two triangles.

What mistakes should I watch for when students complete this worksheet?

Watch for students choosing a law without matching it to the given side-angle information, reversing corresponding sides and angles, or using the wrong value when solving for a missing measurement. In the SSA questions, students may overlook the possibility of two triangles or conclude that a triangle exists when the measurements are impossible. Also check the fill-in responses for nearest-tenth rounding and required units, and the area questions for using the included angle correctly.

How do I assign and grade this Laws of Sines and Cosines worksheet?

The worksheet is available as a printable PDF and as a digital quiz on Wayground, and it includes a complete answer key for checking the law selections, numerical solutions, triangle counts, and area answers. Printable submissions can be graded by scanning student work with the Wayground for Teachers app.

How can I differentiate this worksheet for my students?

Use the worksheet’s Advanced Settings to adjust font spacing or font size so the law-selection prompts, numerical choices, and multi-part triangle-solving item are easier to read. You can also enable a dyslexia-friendly font or translate the worksheet into another language when those options support access to the trigonometry directions and answer prompts.

Where can I find more worksheets like this on Wayground?

Wayground offers a broad collection of free printable worksheets and practice problems across subjects, with downloadable PDFs and answer keys to support essential skills and concepts. Browse more resources at https://wayground.com/en-us/worksheets.