Harry makes a wizard hat by stacking two cones of cardboard so that their axes coincide.

The first cone is obtained from a disc of 18 cm in radius, by cutting along a radius and by overlapping the cardboard on a 60 degree angle.

For the second cone uses a disc of the same radius but with an overlap of 180 degrees.

Calculate the height of each cone, then calculate the total height of the hat to the millimeter illustrating calculation by a drawing.

What is the volume of this hat?

Note: you can use discs with larger radius, so the hat fits everyone's head.

Jean Monnet High School:

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2. Primary school Stevan Dukic, Belgrade, Serbia

 

 

 3. Architectural Technical High School, Belgrade, Serbia