Thanks. A good exercise with students is to get them to calculate the total area of the individual pieces for the two big shapes. Then compare that with the area of the big shape if it was made of just one piece. This should then give them a hint as to how the puzzle might be accomplished. Or they could just look really carefully. ðŸ™‚

I was thinking that students could calculate the slope of the top lines forming the two smaller triangles. Since the slopes aren’t equivalent, the line forming the top of the third triangle isn’t straight. Our eyes can deceive us, can’t they!

Reblogged this on Find the Factors and commented:

This is a fabulous mathematical question!

Thanks. A good exercise with students is to get them to calculate the total area of the individual pieces for the two big shapes. Then compare that with the area of the big shape if it was made of just one piece. This should then give them a hint as to how the puzzle might be accomplished. Or they could just look really carefully. ðŸ™‚

I was thinking that students could calculate the slope of the top lines forming the two smaller triangles. Since the slopes aren’t equivalent, the line forming the top of the third triangle isn’t straight. Our eyes can deceive us, can’t they!

Wonderful idea. Thanks for sharing.

Another puzzle paradox can be found here: https://sciencemagician.wordpress.com/2014/01/30/whats-wrong-with-this-part-2/ Makes a good student investigation relating the angle of the cuts to the size of the central square.