The probability density function (pdf) is;
f(x)=
for a ≤ x ≤ b.
while the mean is given as 
And the standard deviation given as 
Answer:
quadrilateral,parallelogram
Step-by-step explanation:
A quadrilateral is a four-sided polygon.
A parallelogram is a quadrilateral with two sets of parallel sides, much like a rectangle, but with no right angles.