How to Make a Cardboard Boomerang

Gather your materials. To make a cardboard boomerang you will need a few materials ready before you begin. Most of the materials are things you have at home already.

• Cardboard. This can be cardboard from a box, a cereal box, or any other cardboard you have and want to recycle.^[1]
• Ruler or Protractor
• Pen or Pencil
• A marker
• Scissors
• A small water bottle

Draw a perfect square on the cardboard. Use the ruler to measure a medium sized square, about a 10 x 10 inch square. Make sure all four sides of your square are the exact same length and have straight lines.

Cut the square out. Use the scissors to cut out the square of cardboard. Make sure you follow the lines perfectly when cutting out your square so that you end up with a perfect square.

Draw an equilateral triangle on the square of cardboard, and cut it out. It’s important that the arms of your boomerang are all the exact same size, so making it from an equilateral triangle will help. Make sure you measure accurately before cutting.^[2]

• Measure one side of the square and make a mark at the halfway mark.
• Make another halfway mark on the opposite side as well, and use the ruler to draw a straight line between them. This should make a line running down the center of the square.
• Position the square in front of you so that the line is running up to down.
• Use your ruler to draw a line from the top of the first line to the bottom right corner of the square. This line should be the same size as the sides of your square. Repeat this to make a line from the top of the first line to the bottom left corner as well.
• You should now have a triangle shape on your square.
• Use scissors to cut the triangle out.

Mark the center of each side of the triangle, and draw lines from these points. One side of the triangle should already have a line drawn from the center up to the top corner, but you need to mark the center of the other two sides. Use your ruler to measure the sides and make a mark at the halfway point.^[3]

• Use the ruler to draw straight lines from the marks you made to the corner opposite the side the mark is on.
• You should now have a line going directly through the center or each corner of the triangle.

Draw the edges of the boomerang arms. Use the ruler to make marks two inches from either side of the lines going through the corners. Make a straight line going through these marks from the edge to the center of the triangle

• You should end up with two lines running parallel to and two inches away from the line going through each corner of your triangle.
• This will make 3 lines coming from each corner and going to the center of the triangle. These 3 lines make up the arms of the boomerang.

Cut the boomerang shape out. Use a marker to draw over the part of the lines you will cut out. Draw over the outer two lines in each corner starting from the edge of the triangle and stopping where it intersects another line coming from the next corner. It should look like you’re cutting 3 smaller triangles out of the edges of the triangle leaving 3 arms in a “Y” shape. Cut the cardboard where you have drawn with marker.

• You will be cutting 3 small triangles out of the edges of the larger triangle.

Round the edges of the boomerang. Use the water bottle to trace a rounded shape onto the ends of each boomerang arm. Place the water bottle on the end of the boomerang arm and trace the bottom of it onto the arm. This should create an arc going from one edge of the arm to the other edge. Do this with each arm of the boomerang. Cut the end of the arm around the arc you have drawn.

Test your boomerang. Throw your boomerang by holding one of the arms in your hand with the boomerang making a “Y”shape. Fling the boomerang out of your hand at a slight angle, and watch it fly through the air. Test out different angles to find out which one is best for throwing to get the boomerang to come back to you.