a - length of side of a square
t - length of side of a triangle
The perimeter of a square: 
The perimeter of a triangle: 
We have the area of a triangle: 
The formula of an area of an equilateral trinagle: 
Substitute:
<em>multiply both sides by 4</em>
<em>divide both sides by 
</em>
The perimeter of a triangle: 
Substitute to the formula of a perimeter of a square:
<em>divide both sides by 4</em>
The formula of a diagonal of a square: 
Substitute:
The answer is c or the third option. If we start at one we get (4(1)-9)=-5, then we can do 2 and we get (4(2)-9)=-1. Lets do 3 (4(3)-9)=3. Now 4 (4(4)-9)=7. Now 5 and our last one (4(5)-9)=11. Now notice we get -5+-1+3+7+11.
Mph is what you are going for
so 171/3 = 57
57mph is your answer
hope this helps
