After examining the square table with grids to fit the triangle tiles, my calculation is 20 triangular tiles are used. Here is how I came up with the answer. Inside the table, it consists of four different shapes in triangle, rectangle, square, and a right-angle trapezoid. A square requires four tiles to fill. A rectangle requires two triangle tiles, as it is half of the square. On the other hand, the trapezoid allows three tiles to fill, as one side of triangle is missing.
I carefully studied the square table and looked at the proportion of the size of triangle, I was confident to determine the number of tiles were correct. Thus, the mathematics I used to solve this question was Measurement and Geometry which involves in using the relationship