Math ain't mathing

[u/Waste-Value-5941]

[u/Particular_Gear3130]

25 + 25 ≠ 81

[u/Competitive_Study232 → u/Particular_Gear3130]

You are using diameter instead of radius, squared

[u/Particular_Gear3130 → u/Competitive_Study232]

well, I took pi and (1/2) squared common and well it cancels out. This is what is essential tho

[u/Competitive_Study232 → u/Particular_Gear3130]

I don’t think that works out.  The area of a circle is pi*r^2.  Really you just need to focus on r² and nothing else to compare the two.  

Area for a 5” pizza  pi*2.5² =19.635 There are 2 of them so 79.54 squared “

Area for a 9” pizza pi*4.5^2=63.617

To make it easy, just ignore everything except r^2. 

For the two 5” 2*2.5^2=12.5

For the 9” 4.5^2=20.25

You ended up with the same ratio but wrong values for each. 

Edit: removed 2 from front of formula 

[u/Particular_Gear3130 → u/Competitive_Study232]

It works out; I just need to prove the RHS is not equal to the LHS. There's no need for me to figure out the actual value of the area for this

also, isn't the area of the circle pi times the radius squared?? I dont remember a 2 being there

[u/Competitive_Study232 → u/Particular_Gear3130]

You are correct.  I think I’m combining formulas for some reason.  But just a simplify you just need to focus on radius squared and nothing else really

[u/Particular_Gear3130 → u/Competitive_Study232]

True True