Answer:
Part 4)

Part 5a)

Part 5b)

Part 5c) see the explanation
Explanation:
Part 4) we know that
The Midpoint Theorem says that the line segment joining the midpoints of any two sides of a triangle is parallel to the third side and equal to half of the third side
so in this problem
Applying the midpoint theorem

Part 5) we have

Part a) Determine the coordinates of J, the midpoint of MA
we know that
The formula to calculate the midpoint between two points is equal to

we have

substitute


Part b) Determine the coordinates of L, the midpoint of AN
we know that
The formula to calculate the midpoint between two points is equal to

we have

substitute


Part c) Prove that JL=1/2MN
we know that
the formula to calculate the distance between two points is equal to

Find the distance JL
we have

substitute the values in the formula



Find the distance MN
we have

substitute the values in the formula



simplify

Prove that

substitute the values

---> is true
therefore
Is verified