The way to do it can be explained like this:
Say AB and CD are the two parallel lines cut by a transversal at E and F respectively.
Then the pairs of alternate interior angles are:
Angle(AEF) and Angle(DFE)
Angle(CFE) and Angle(BEF)
Now lets prove if this is true:
<span>Angle(CFE) +Angle(DFE) = 180
(linear pair)
Also
Angle(CFE) +Angle(AEF) = 180
(Corresponding angles)
</span><span>Equate the above results:
Angle(CFE) +Angle(DFE) = Angle(CFE) +Angle(AEF)
</span><span>Angle(DFE) = Angle(AEF)
</span>Happens the same with
<span>Angle(CFE) = Angle(BEF)
</span>Hope this is very useful for you
Answer:

Step-by-step explanation:
Use the formula for a semicircle's perimeter.

Plug in 6 for d.

Let's use 3.14 for
, just to make it easier, but of course, if it states to round it to something else, just plug in that many values for
.
