Answer:
Part 10)
a) 
b) 
c) 
d) 
Part 12) x=11
Part 14) see the explanation
Step-by-step explanation:
Part 10) we know that
In a square all four sides are congruent
The diagonals of a square are congruent and bisect each other at right angles
Part a)
Find the length of diagonal OM
we know that
---> the diagonals are congruent
we have

therefore

Part b)
Find the length of PN
we know that
---> remember that the diagonals bisect each other

we have

substitute

Part c)
Find the length of ON
Applying the Pythagorean Theorem

we know that
----> remember that all four sides are congruent
so


substitute




simplify

Part d)
Find the length of MN
we know that
----> remember that all four sides are congruent
we have

therefore

Part 12) we know that
The diagonals of a square bisect its angles
Remember that the interior angles of a square is 90 degrees
so

solve for x

Part 14) we know that
A parallelogram has opposite parallel sides, so a parallelogram will always have consecutive supplementary angles.
The rectangle, rhombus and a square are all parallelograms
therefore
parallelograms, rectangles,rhombi and squares will always have consecutive supplementary angles.