Answer: 8/343
Step-by-Step:
If two similar solids have a scale factor of a:b then,
The ratio of their surface areas (2D) is- a^2:b^2
The ratio of their volume (3D) is- a^3:b^3
First you want to square root the scale factor numbers to find the original value. Then you cube the original numbers to find the answer.
Standard form is ax+by=c
normally a is positive and a and b are integres
y=mx+b
m=slope
b=yint
y=1/2x+3
minus 1/2 x both sides
-1/2x+y=3
times -2
x-2y=-6
The area is that of two 20 yd squares and one 20 yd circle.
.. A = 2*(20 yd)^2 +(π/4)*(20 yd)^2
.. = (2 +π/4)*(400 yd^2)
.. = (800 +100π) yd^2
.. ≈ 1114.16 yd^2
The perimeter is that of a 20 yd circle and 80 yd more.
.. P = π*20 yd + 80 yd
.. ≈ 142.83 yd