A Tangled Web

Angles, from basic rules to circle theorems

Help Itzi the spider climb the clock to rescue his family! Solve cunning angle puzzles to reveal a path through each level’s maze of tangled webs and reach the goal. It’s sure to make your head spin!

Basic angle rules, Parallel lines, Polygons, Circle theorems


Game Goals

In this math game you control a tiny robotic spider named Itzi, who lives with his family at the top of a strange old grandfather clock.

One dark night, the clock struck midnight with a mighty mechanical ‘Clang!’. So loud was the noise that the whole clock rattled and shook, sending Itzi and his family tumbling down through its rusty innards. Now Itzi must climb back up the clock, rescue his stranded family members, and return home!

On each level Itzi must find a safe path through an intricate maze of tangled webs, solving cunning angle puzzles as he goes. You’ll need brains and bravery to succeed, so get going – Itzi’s family are depending on you!

How To Play

To start a game, click ‘Play’ and then ‘OK’ to skip past the family portrait. (As you rescue family members, their images appear in the portrait – save everyone to complete the painting!)

On the ‘Select Level’ screen, click on any unlocked level to begin play (locked levels are indicated by a padlock symbol). The first time you play, only Stage 1: Level 1 is available.

In each level, your ultimate goal is to guide Itzi safely to the Warp Gate. You don’t control Itzi’s movement directly; instead, you rotate the giant cog and then Itzi ‘rolls’ according to gravity.

Dotted around each level are blue Glo-Flies. Itzi must collect all the blue Glo-Flies to activate the Warp Gate – only then can he enter it and travel to the next level.

On some levels you will find special gold Glo-Flies. You don’t have to collect them to activate the Gate, but they’re worth big bonus points if you do. Typically gold Glo-Flies are tucked away in hard-to-reach places, designed to challenge expert players. If you can’t reach one on your first play-through, that’s okay – just move on and come back later when you’ve honed your skills!

At certain points, Itzi’s path to the Gate will be blocked by a coloured line. To remove the line, you must click on the angle puzzle of the same colour and input its value:

Itzi’s energy is shown by a bar in the top-left of the screen – if it runs out, you fail the level. You also fail the level if you don’t reach the Gate before time runs out. But don’t worry: you can always try again!

Itzi also loses energy if he hits the cog rim or bumps into dangerous obstacles, such as Laser Walls and Spike Balls.

Game Controls

The game can be controlled entirely with the mouse, or by a combination of mouse and keyboard – to enjoy the game at its best, we recommend the latter.

To rotate the cog and roll Itzi around the level, press the left and right arrow keys (when in Window mode, you can also use the A and D keys). If you prefer, you can also rotate the cog by clicking on the arrow buttons to the right of the screen.

To input angle values, first click on the angle to make an input box appear. Now enter the angle’s value using either the keyboard or the on-screen keypad. For faster play, you can also click on the input box again to confirm entries or to close it.

Removed lines reappear after a few seconds, but can be removed again by clicking on the angle (you don’t need to solve the puzzle again).

Should you get stuck and want to start the level afresh, click on the ‘Restart‘ button in the bottom-left corner of the screen (next to the 'Pause' and 'Help' buttons).

Notes Function

In more complex levels there will be times when you want to record important info, such as the sum of certain angles or the values of unlabelled angles. Don’t reach for a pen and paper – use the Notes function!

It’s easy to use: first double-click on any empty area inside the cog to create an input box, then enter the value you want to record (like when solving angle puzzles). Hey presto, your value is now displayed on-screen! The Notes function can be really useful, so be sure to make good use of it.

If you need to erase a Note, simply point at it (the mouse pointer will change to an eraser icon) and click.

Stages & Levels

This game features six Stages, each of which focuses on a different area of angles-related mathematics:

Stage 1: Basics
  • Angles at a right angle
  • Angles on a line
  • Angles at a point
  • Vertically opposite angles
Stage 2: Parallel Lines
  • Corresponding angles
  • Alternate angles
  • Interior angles
Stage 3: Triangles
  • Angles in a scalene triangle
  • Angles in an isosceles triangle
  • Angles in an equilateral triangle
  • Exterior angles of a triangle
Stage 4: Quadrilaterals
  • Angles in a rectangle and square
  • Angles in a quadrilateral (i.e. a quadrilateral with no special properties)
  • Angles in a parallelogram and rhombus
  • Angles in a kite
  • Angles in a trapezoid
Stage 5: Polygons
  • Exterior angles of a polygon
  • Interior angles of a polygon
Stage 6: Angles In Circles
  • Triangles in circles
  • Radius and chord bisection rule
  • Right angle in a semi-circle rule
  • Cyclic quadrilateral rule
  • Angle at the center is twice the angle at the circumference rule
  • Angles in the same segment are equal rule
  • Radius and tangent perpendicularity rule
  • Alternate segment theorem rule

When the ‘Select Level’ screen appears after starting a new game, the highest Stage reached is displayed by default. To play earlier Stages, simply click the Stage number on the clock to the left of the screen. The first time you play only Stage 1 is available, with higher Stages unlocking once you reach a certain Total Score.

Each Stage consists of 20 standard levels. When you first play a Stage, only Level 1 is available; as you complete each level, the next in sequence unlocks automatically. One of your lost family members awaits rescue at the end of each Stage – complete Level 20 to save them!

In each Stage, as well as the standard levels there are four secret bonus levels, each containing a special challenge designed for gaming masters! To unlock the first bonus level you must achieve C Rank or better in all 20 standard levels; to unlock the second you must achieve B Rank or better; to unlock the third, achieve A Rank or better; and to unlock the fourth, achieve S Rank.

Note that the bonus levels are not available in Challenge mode.


Your score for each level is the sum of four values:

Level Score = Energy Score + Blue Glo-Flies Score + Gold Glo-Flies Score + Time Bonus
Energy Score
3,000 points × % energy remaining
Blue Glo-Flies Score
500 points × blue Glo-Flies collected
Gold Glo-Flies Score
1,000 points × gold Glo-Flies collected
Time Bonus
1 point × seconds remaining

Example 1: You complete a level with 75% energy remaining (3,000 × 0.75 = 2,250 points) and with 78 seconds left on the timer (78 points). You collected 3 blue Glo-Flies (3 × 500 = 1,500 points) and no gold Glo-Flies (0 points).
So your score for the level is: 2,250 + 1,500 + 0 + 78 = 3,828 points.

Example 2: You complete a level with 40% energy remaining (3,000 × 0.4 = 1,200 points) and with 143 seconds left on the timer (143 points). You collected 2 blue Glo-Flies (2 × 500 = 1,000 points) and 2 gold Glo-Flies (2 × 1,000 = 2,000 points).
So your score for the level is: 1,200 + 1,000 + 2,000 + 142 = 4,343 points.

Your best score for each level is recorded automatically. The scores for all levels completed in a Stage are added together to create the Stage Score, and the scores for all unlocked Stages are added together to create the Total Score.

On completing a level you are awarded a Rank of either C (OK), B (Good), A (Great) or S (Amazing!). These are defined as:\

C Rank
Complete the level with score equivalent to less than 66% energy remaining and no time bonus.
B Rank
Complete the level with score equivalent to more than 66% energy remaining and no time bonus.
A Rank
Complete the level with score equivalent to 100% energy remaining, all gold Glo-Flies collected and no time bonus.
S Rank
Complete the level with score equivalent to 100% energy remaining, all gold Glo-Flies collected and a fast time bonus. S Ranks can be tough to get – look for shortcuts and tricks that will help you save seconds!

Improve your score

Basic Strategies

Math Strategies