KHAN ACADEMY LINK TO Lines, line segments, and rays: Difference between lines, line segments, and rays
Estimating Angles Shoot the Spaceship An alien speceship will appear on the screen.
Click the + and  buttons to set the laser's angle correctly towards the alien.
Click the "fire" button to shoot the laser.   Setting the Correct Angle Playground In every trial you will be given a target  one of the objects of the playground (the dog, the castle, the slide etc.).
Set an angle Using the red arrows, and drag it onto the hose. Then the hose will rotate according to the angle given, and hopefully will squirt the water on the correct target. 

Setting the Correct Angle Kung Fu Angles You are a Kung Fu warrior and you are standing in the middle of a circle. Your opponent is standing somewhere on the circle.
Type the correct angle you have to turn in order to face your opponent.
  Estimating Angles Telescope Star Gazing Eight stars are located in the sky.
Your job is to spot them with your telescope.
Type the number of degrees to rotate it, and click the "Point Telescope" Button.
Try to make it on time before the sunrise! 

Rotating Angles Clockwise and CounterClockwise Fruit Picker Fruits are located around half a circle.
Your job is to pick them up by turning your picker with the correct angle, clockwise or counterclockwise.
Plan your movements carefully in order to pick all the fruits with the least number of angle rotations.   Estimating Angles Alien Angles In every trial you will be given a number which represents the alien's angle, and your job is to recreate this angle with lines, as accurately as possible.
When you are ready, click the "Check It" button and a missile will shoot along the line you set.
If you were accurate enough, the missile will hit the alien. 
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