Answer:
Part 1) 
Part 2) 
Part 3) 
Step-by-step explanation:
Part 1) Find AC
we know that
In the right triangle ABC of the figure
Applying the Pythagorean Theorem

substitute the given values


Part 2) Find the measure of angle A
we know that
In the right triangle ABC
----> by TOA (opposite side divided by the adjacent side)
substitute the values

using a calculator

Part 3) Find the measure of angle C
we know that
In the right triangle ABC
----> by complementary angles
substitute the given value


To get a decimal form of a fraction, divide the numerator by the denominator.
7/8 = 0.875
Answer:
The circle's diameter is 
Step-by-step explanation:
we know that
The circumference of a circle is equal to

where
D is the diameter of the circle
In this problem we have


substitute the values and solve for D


Answer:
x = 83
Step-by-step explanation:
The sum of the angles of a quadrilateral is 360
75+x+97+105 = 360
Combine like terms
x+277=360
Subtract 277 from each side
x+277-277=360-277
x = 83