False. When a quadrilateral has two sets of parallel sides ,like I drew below, all four corners form right angles.
Explanation:
Let the equation be
a
⋅
x
2
+
b
⋅
x
+
c
. To factorize multiplication of a and c i.e. ac so that sum of factors, if ac is positive (and difference if ac is negative) is equal to b. Now split b into these two components and factorization will be easy.