The coordinates of the vertices of a quadrilateral are (8, 11) (11, 7) (8, 3) (2, 3). What is the area, in square units, of the quadrilateral?

Check the picture below.

so the quadrilateral is really just a parallelogram below a triangle, so let's simply get the area of each and sum them up.

The total nom of  code that can be used is equal to 5+3 = 8

The solution is in the following image

The answer is in the image 

Salesperson will make 6% of 1800

=(6/100)*1800

=108

Salesperson will make $108 in $1800 sales

The answer is in the image 

The solution is given in the image below

The wood before starting =12 feet

Left wood=6 feet

Wood used till now=12-6=6 feet

Picture frame built till now= 6/(3/4)

=8 pieces

Therefore, till now 8 pieces have been made.

The answer is in the image 

30% of 420 are first year students

first year students = (30/100 )*420

=126 students

Student who are not in first year = 420-126

=294 students