Free teaching resource

Mini-Mystery – Which Key Opens the Door?

Teach Starter Publishing
PDF | 1 page | Years: 4 - 5

Use knowledge of 2-D shapes and right angles to solve the mystery in this fun, logic-based activity.

Can we trust those triangles?! 

In this engaging maths activity, students review 2D shapes and right angles to find the correct key. 

Read the statements made by the characters and use logic and reasoning to eliminate ‘red herring’ characters who are trying to trick you! By combining the statements made by the characters with the Cold Hard Facts at the bottom of the page, students then decide which key opens the door.

piece of paper with a kids logic puzzle worksheet is laid out on a desk beside it to the left is a key

Right Angles and 2D Shapes Worksheet: Scaffolding and Extension Tips 

This teaching resource can be an engaging maths warm-up exercise, a fast finishers task, or even a fun indoor break activity. 

Students must use their knowledge of 2D shapes and right angles to help solve the mystery.

In addition to individual student work time, use this 2D shapes worksheet as a:

Not only does this mini-mystery activity help your students with their memory and logical thinking, but it also provides learners with an opportunity to read between the lines.

In addition to solving the worksheet, students can also colour it.  

A Variety of Ways to Prepare This Resource

Because this resource includes an answer sheet, we recommend you print one copy of the entire file. Then, make photocopies of the blank worksheet for students to complete.  

You can also turn this teaching resource into a sustainable activity! Print a few copies on cardstock and slip them into dry-erase sleeves. Students can record their answers with a dry-erase marker, then erase and reuse. 

Additionally, project the worksheet onto a screen and work through it as a class.

Before You Download

Use the dropdown icon on the Download button to choose between the PDF or Google Slides version of this resource. An answer key is also included with this download.

Get more handy worksheets here!

Don’t Stop There

We’ve got more 2-D Shapes Teaching Resources to cut down on lesson planning time:  

Image of Tangram Treats – Task Cards and Templates

teaching resource

Tangram Treats – Task Cards and Templates

Explore the properties of geometric shapes with this set of scaffolded tangram shapes task cards and cut-out tangram templates.

Teach Starter Publishing37 pagesYears: 2 - 6
Image of Let's Sort It! - 2D Shapes and 3D Objects Sorting Activity

teaching resource

Let's Sort It! - 2D Shapes and 3D Objects Sorting Activity

A sorting game to use in the classroom when identifying the properties of 2D shapes and 3D objects.

Teach Starter Publishing9 pagesYear: 2
Image of 2D Shape Bingo

teaching resource

2D Shape Bingo

30 different bingo cards using 2D shape pictures and names.

Teach Starter Publishing18 pagesYears: 2 - 7Has Starter Sheet


Write a review to help other teachers and parents like yourself. If you'd like to request a change to this resource, or report an error, select the corresponding tab above.

Log in to comment
  • Alana Turner

    My year 5 kids LOVED these activities! Any chance of some more?? Thanks so much TeachStarter

    • Paul (Teach Starter)

      Hi Alana, Thanks for your feedback! Please feel free to request a resource at our 'Request a Resource' page. Requests are voted on by the Teach Starter community and we create the top requests. Please let me know if you have any further questions, I’m more than happy to help.

  • Zayleigh

    that is so cool

    • Paul (Teach Starter)

      Hi Zoe, Thanks for your comment! We're glad you like the mini-mystery!