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Kiwiland Education

Right Triangle Trigonometry | Math Mystery Worksheets | Grades 9–11 | Sine Cosine Tangent

$4.50 USD

SOHCAHTOA becomes a worksite investigation across seven cases — students find the missing side or angle of each right triangle, write the answer in the box beside it, match it to a suspect, and cross suspects off until one is left standing. This no-prep, printable, self-checking Math Mystery keeps geometry and Algebra 2 students engaged and works for math centers, bell work, homework, early finishers, substitute/relief days, spiral review, and test prep. The first five cases find sides; the last two switch to inverse trig and missing angles.

Quick Details

Skill: Right triangle trigonometry — sine, cosine, tangent and their inverses · Grades: 9–11 · Format: 7 mysteries + full answer keys (printable PDF) · Theme: Engineering worksite

The 7 Mysteries

The Roof Pitch Puzzle — The roof plans on the site have all been switched, and students find the missing side of each right triangle to work out who did it.

The Flagpole File — Every flagpole on the parade ground was reset overnight.

The Sign Post Swap — The signs outside every shop have been swapped around.

The Zip Line Zigzag — Someone re-strung the zip lines at the adventure park, and each case turns on finding the hypotenuse.

The Drawbridge Dodge — The drawbridge drawings came back from the printer wrong.

The Crane Arm Caper — The dockyard cranes were all left at the wrong setting, so students find the size of each missing angle.

The Radar Room Ruse — Every radar screen in the tower is reading the wrong bearing, and inverse trig is the only way to the answer.

Why Teachers Love It

Zero prep — print and teach. The built-in answer keys make every case self-checking, so students get instant feedback and stay motivated. The detective hook pulls in reluctant and struggling learners, and because the pack moves from finding sides to finding angles, one file covers both halves of the unit.

Skills Covered

Choosing the correct ratio from SOHCAHTOA, finding a missing leg, finding the hypotenuse, using inverse sine, cosine and tangent to find a missing angle, and labelling opposite, adjacent and hypotenuse correctly — plus logical reasoning and deductive elimination as students rule suspects out clue by clue.

What's Included

Printable one-page mystery worksheets, a labelled right triangle on every problem, suspect line-ups, complete answer keys with the villain marked, and student instructions — all in one PDF.

Best Used For

Trigonometry practice in math centers, bell work, homework, early finishers, substitute/relief days, spiral review, and end-of-unit test prep for grades 9–11.

More From This Line

Browse every Math Mystery pack, or keep the geometry unit going with Pythagorean Theorem and Volume of Cylinders, Cones and Spheres.

All of our products are digital downloads — no physical items will be shipped.

  • After purchase, you’ll receive an email with a download link within minutes.
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  • If you experience any issues accessing your files, please contact us and we’ll help you promptly.

Due to the nature of digital products, all sales are final.

We do not offer refunds or exchanges once a file has been downloaded.

However, if you encounter any problems with your download or the product itself, please reach out — we're happy to assist.

  • Thank you from Kiwiland Education

How Math Mysteries Work

Each Math Mystery resource gives you five one-page cases that turn math practice into a clue-based investigation. Here's exactly how a case plays out.

CASE FILE 5 MYSTERIES

Every set is a ready-to-solve investigation

Students become the math detective. They read a story, crunch the numbers, and use their answers as evidence to rule out suspects — until only the culprit is left standing.

1
STEP 01

Read the Case

Each mystery opens with a short, themed story that sets the scene and tells students exactly what they're trying to find out — who took something, what went missing, or what really happened.

Hooks them in seconds
2
STEP 02

Solve the Problems

Students work through a set of problems built around the target skill. Every answer is a clue — so there's a real reason to get each one right.

Focused skill practice
3
STEP 03

Eliminate Suspects

Students match their answers against the suspect list and cross off names one clue at a time. Wrong math means the wrong suspect — so the activity self-checks as they go.

Self-checking built in
4
STEP 04

Crack the Case

One suspect is left — and students reveal who did it. The payoff makes review feel like a win, and they're ready to start the next case.

The satisfying reveal

See it in action

SOLVE A CLUEAnswer = 576
MATCH THE ANSWER576 = Bianca
CROSS OFFBianca
No apps. No logins. No prep. Just print, hand out, and let them investigate.

New to the format? Read What Is a Math Mystery? for how they work and how to run one in class.

Why Teachers Use Math Mysteries

Skill practice that feels like a case worth solving — and a download that quietly does a lot of your planning for you.

5one-page cases per set
0prep or setup time
color & black-and-white
answer keys included

Five Mysteries in One

Every download includes five separate one-page cases — enough for a full week of practice, a center rotation, or a sub-day backup that's always ready to go.

Truly No-Prep

No cutting, laminating, apps, or logins. Print in full color or black-and-white and hand them straight out — that's the whole setup.

Self-Checking by Design

Students need the right answers to rule out the right suspects, so accuracy matters — and the included answer keys mean no grading for you.

Fits Any Routine

Use one case as a morning warm-up, or spread the five across the week for centers, partner work, early finishers, or intervention.

Keeps Students Hooked

The mystery format gives even reluctant mathematicians a reason to keep solving. Review starts to feel like a game, not another worksheet.

Differentiation-Friendly

Great for on-level practice, an extension for advanced students, or a targeted review pass for anyone who needs another go at the skill.

NO PREP PRINT & GO ANSWER KEYS INCLUDED

What's in every Math Mystery set

5 full-color mysteries 5 black-and-white versions 5 complete answer keys Print-and-go teacher page Bonus coloring page
Practice that feels like a case worth cracking.

Frequently Asked Questions About Math Mysteries

Printable Math Mystery worksheets that turn math practice into clue-based detective investigations.

Is this Math Mystery a digital activity?

No. This is a printable PDF resource. Students complete the Math Mystery on paper. No physical item will be shipped.

Do students need apps, locks, passwords, or logins?

No. Students do not need apps, locks, passwords, or logins. Teachers can print the pages and use the Math Mystery straight away.

How do students solve the Math Mystery?

Each resource includes five one-page cases. In each one, students solve the math problems and use their answers to eliminate suspects until only one remains and the case is cracked.

Can this Math Mystery be used for sub plans?

Yes. Math Mysteries work well for sub plans because students can work through the clues independently, with a partner, or in small groups.

Can this Math Mystery be used for homeschool?

Yes. This printable Math Mystery can be used for homeschool lessons, tutoring, review practice, enrichment, or extra math support.

Will this work for early finishers or math centers?

Yes. Math Mysteries are a good fit for early finishers, math centers, small groups, independent work, review lessons, and extra practice activities.



Right triangle trigonometry math mystery worksheets for geometry grades 9 to 11, no prep printable

Right Triangle Trigonometry | Math Mystery Worksheets | Grades 9–11 | Sine Cosine Tangent

$4.50

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