Answer:
B Allied Powers
Step-by-step explanation:
They worked with the US during WWI and WWII
Because its a square all its sides are 5cm
So area of square is 5x5=25cm^2
Triangle is 5x4= 20
20/2 is 10cm^2
25+10=35cm^2
X/10 = 10/4x
4x^2 = 100
x^2 = 25
x = 5
answer
5 units
So I first subtracted 3x on each side, then 2x would equal 40 and then to find x, divide both sides by 2