they are 2 similar triangles, one is smaller than the other. they are in the ratio of 2:1,
hence 7x =56÷2
7x=28
x=4
You basically add 17.50+17.50=35 and add 35+35=70, reason being is because the 35 is the 1/2 and 17.50 is the 1/4 so 70 is your answer