This is an excellent practice for the solution of quadratic equations.
1*36=36 => (1,36)
2*18=36 => (2,18)
3*12=36 => (3,12)
4*9=36 => (4,9)
6*6=36 => (6,6)
9*4=36 => (9,4)
12*3=36 => (12,3)
18*2=36 => (18,2)
36*1=36 => (36,1)
We can see that the sum decreases until the two factors are close (or equal) and then increases again.
The pair of integers with a sum of 20 is therefore (2,18) or (18,2).
Answer:
It is an irrational number because 
is irrational
2 oranges cost $2 . $9 - $2 = $7
then 12 apply of Lisa and 6 apples of Jeremy
= 18 ÷ 7 = 2.57. $2.57 for 6 apples
2.57 ÷ 6 = 0.43 each apple
This most definitely has to be a rhombus since it is a form of a square with 4 congruent sides where a rectangle only has 4 right angles.
To clarify, a trapezoid only has one pair of parallel sides if you were wondering.
