The ratio of boys to girls is 12 to 16, 12:16 or 12/16 (all different ways this can be written). The fraction form 12/16 can be reduced by dividing by the greatest common factor. Both 12 and 16 are divisible by 4, so the reduced fraction is 12/4 over 16/4 = 3/4. In other words, there are 3 boys for every 4 girls in the class.
Reflecting it across the lines will bring the triangle on to the other triangles. This will show that when the triangle goes under a transformation such as reflection, the angles will stay the same.
