Angle Explorer Game
Free angles game: drag an arm to make acute, right, obtuse and reflex angles, build exact angles on a protractor, estimate their size and find missing angles.
Level 1 asks for an angle type: drag the arm until the angle is acute, right, obtuse, straight or reflex. Level 2 shows a protractor and asks for an exact size such as 65°. Level 3 hides the protractor: choose the closest of three sizes. Level 4 works out x on a straight line, in a right angle, a triangle or around a point. The arm snaps to 5° steps and can also be moved with the arrow keys.
Drag the arm to make an acute, right, obtuse, straight or reflex angle.
Not a test — nothing is saved after you leave.
Make, measure and work out angles
Drag the arm to build angles, read them on a protractor, estimate their size and work out missing angles.
How to use the angle explorer game
- 1Choose a level: make the type, make the size, estimate, or missing angles.
- 2Drag the round handle at the end of the arm (or focus it and use the arrow keys), then press Check.
- 3On Estimate, tap the closest size; on Missing angles, type x and press Enter.
- 4Read the explanation, then press Next. A round is 8 questions.
When this is useful
Angle types
Building an angle of each type shows the boundaries: exactly 90° for a right angle, exactly 180° for a straight angle.
Protractor practice
Level 2 uses the same double-scale protractor as the Angles Worksheet Generator, so students practice choosing the scale.
Estimation
Comparing with a right angle first makes measuring faster and catches scale mistakes.
Angle facts
Level 4 practices the facts behind most angle problems: 180° on a line, 90° in a right angle, 180° in a triangle, 360° around a point.
Examples to try
Level 1
Make an obtuse angle: any size between 90° and 180° counts.
Level 2
Make 135°: from the fixed arm's 0, read 135 on the same scale.
Level 4
A triangle with 60° and 65°: x = 180 − 60 − 65 = 55°.
Tips for better results
Find the zero first
On the protractor, start from the 0 on the fixed arm and stay on that scale.
Estimate before you drag
Is the target smaller or bigger than a right angle?
Pair it with paper
The Angles Worksheet Generator prints the same three skills with an answer key.
How the angle explorer game works
The arm snaps to 5° steps, so every target can be made exactly. Missing-angle questions come from the angles worksheet engine, which builds every figure to scale and checks every answer in its tests. Rounds are generated on your device with a seeded generator.
Private by design
- No account and no sign-up. Just open it and start.
- Everything runs on your device, which keeps the angles you make and the answers you type during a round private.
- Nothing you create is uploaded. No values, names, scores, or generated content are sent to our servers. If you're signed in, My Classeem's Recent Activity notes which tools you used — never what you did in them.
- We use Google Analytics for anonymous, aggregate measurement: page views and a few usage events, such as a worksheet being printed or a game round starting or finishing (with the mode played). It never receives what you enter — no answers, scores, names, or generated content.
Frequently asked questions
Is this angles game free?
Yes. No account, no ads and no limit on rounds.
What grades is it for?
Angle types and protractors are usually taught in grades 4 and 5; missing angles in grades 5 to 7.
Can I play without a mouse?
Yes. Focus the round handle with Tab and turn the arm with the arrow keys (5° a step, 15° with Page Up and Page Down).
Does it work on a phone or tablet?
Yes. Drag the handle with a finger; the board scales to the screen.
Does it use AI?
No. Everything is generated and checked by fixed rules in your browser.
More classroom tools
Angles Worksheet Generator
Printable angle practice: name angles, measure them on a drawn protractor and find missing angles, with an answer key.
2D and 3D Shapes Game
Flat or solid? Name the shape, then count sides and corners — or faces, edges and vertices on cubes, prisms and pyramids.
Coordinate Grid Hunt
Name a marked point, plot a point from its coordinates, or find hidden treasure from clues about x and y — in one quadrant or four.
Always free · No account needed · Nothing you type leaves your device unless you choose to save it.