3. 12 a
4. 7b-10
all you have to do is add up all of the sides.
Answer: the first one is 3y
Step-by-step explanation:
Go to the website mathpapa , type in the problem and it gives you the answer with steps
P(7,6), Q(1,6), R(4,2)
We have PQ parallel to the x axis. We'll call that the base,
b = 7 - 1 = 6
The altitude is then the y difference h = 6 - 2 = 4
The area is 
Answer: 12 square units
In general we can use the shoelace formula for the area of any polygon given coordinates. We write the points like this:
(7,6), (1,6), (4,2)
(1,6), (4,2), (7,6)
The area is then half the absolute value of the sum of the cross products:

Answer:
Step-by-step explanation:
Comment
The way the diagram looks when it is drawn is that you are going to need the sine function to solve for the side opposite which is CD.
Formula
Sin(A) = Sin(68 = opposite / hypotenuse Substitute values.
Solution
sin(68) = altitude (side opposite) / 20 multiply both sides by 20
20*sin(68) = 20* altitude / 20 substitute for sin(68)
20* 0.9272 = altitude
altitude = 18.5
Answer: 18.5 to the nearest tenth
75,314 because it is only 5 numbers so this is correct.