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
A is the answer because to find a area you need to multiply each side
well, what variable are you solving for? like if you're solving for x, it would be:
tg is greater than or equal to 0x
Green = 6
Yellow = 2
6 + 2 = 8
8/20 can be simplified to 2/5