Answer:
The length of the diagonal of a poster board is 
Step-by-step explanation:
Let
x----> the length of the diagonal of a poster board
we know that
Applying the Pythagoras Theorem

When eggs = 2, then potatoes = 5
Eggs: 2
Potatoes: 5
When that is changed to 6 eggs, 2 needs to be multiplied by a number to get 6.
2 * what = 6 or 6/2=
you get the number 3. A fraction is equivalent to a ratio. So if you have 2*3=6 then you need to multiply 5*3 to get the amount of potatoes you need. the answer is 15 potatoes because 5*3=15.
B. 16 cm
Square both 20 and 12
20x20=400
12x12=144
400-144=256
find the square root of 256
and the square root is 16
so b is 16 cm