Multiply all sides by 10. make our life easier.
141-3x=13x-42
-16x=-183
divide by -16 both sides
x=11.4375
Answer:
D. 420
The area of a triangle is

half of(base× height)
10×16= 160
160÷2=80
That is the surface area of ONE triangle.
multiply 80 by 4 to get 320
then find the surface area of the square by doing length×width to get 100
Finally add them together
320+100=420
For this, we will be using Triangle Angle Sum Theorem (all interior angles in a triangle add up to 180°) for Triangle BCD. Since Angle CBD and BDC are congruent to each other and Angle BDA, we can solve for those two angles to get that angle. Our equation will look like this:
Firstly, subtract 35 on both sides of the equation: 
Next, divide both sides by 2 and your answer will be 72.5 = x.
Since Angle CBD and BDC are 72.5°, this means that Angle BDA is 72.5° as well.
I really don’t know but I think I got it wrong