Answer:
10
Step-by-step explanation:
Area of traingle:1/2
50=1/2.10.x
50=5x
50/5=5x/5
x=50/5
x=10
any idea about the length of the box
4x+4
factor
4(x+1)
2(2x+2)
x+3x+42x+2x+1+3
Choices B,C,D