85700
8570
85.7
8.57
0.857
Each time, you divide by 10 (move the decimal place 1 place value to the left).
There are two triangles that are 15cm in height and 10cm in width so you do 15 times 10 which is 150 then divided it by 2 because it a triangle to get 75 then because there is 2 you then multiply it by 2 again and you get 150
