How can this be true From where comes this hole?

Answer 1

The reason of the lack of the hole caused by the difference is too small and we can not recognise by optical view, it can be proved by the fomular as below: Assume that the square of one cell is 1 The first picture Total square of the largest triangle equals (8*13)*1/2=32.5 The square of retangle equals = 3*5 = 15 The square of small striangle equals = (5*2)*1/2=5 The square of large striangle equals = (8*3)*1/2=12 => the squares of 2 small triangle do not equal 17 (5+12) => the difference between 17 and 32.5-15=17.5 is so small => we can not recognise by eyes => one of the triangle or both of them are not triangle, it may be a trapezium The reason of the lack of the hole caused by the difference is too small and we can not recognise by optical view, it can be proved by the fomular as below: Assume that the square of one cell is 1 The first picture Total square of the largest triangle equals (8*13)*1/2=32.5 The square of retangle equals = 3*5 = 15 The square of small striangle equals = (5*2)*1/2=5 The square of large striangle equals = (8*3)*1/2=12 => the squares of 2 small triangle do not equal 17 (5+12) => the difference between 17 and 32.5-15=17.5 is so small => we can not recognise by eyes => one of the triangle or both of them are not triangle, it may be a trapezium