<h2>
Answer:</h2>
The area of the top surface of the washer is: 160.14 square mm.
<h2>
Step-by-step explanation:</h2>
The top of the surface is in the shape of a annulus with a outer radius of 10 mm and a inner radius of 7 mm ( since the diameter of the hole is: 14 mm and we know that the radius is half of the diameter)
Now, we know that the area of the annulus region is given by:

where R is the outer radius and r is the inner radius.
Here we have:

Hence, we have:

Answer:
3/4
x 180/
= <u>135°</u>
Step-by-step explanation:
7. Straight lines are also = to 180°
If you look at the diagram, when you add the two angles together, they form a straight line.
Since the angles add up to 180°, you can do:
(x + 25)° + (4x + 5)° = 180°
x + 25 + 4x + 5 = 180 Combine like terms
5x + 30 = 180 Subtract 30 on both sides
5x = 150 Divide 5 on both sides
x = 30
8-9n=15 I believe
At least I hope