Answer:
15.

16.
= 
=
(if needed)
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17.

18.
= 
Step-by-step explanation:
15. The two following angles, which is
and
, are <u>Corresponding Angles</u>. Write an expression by using the following measurements from
and
. Then, solve the expression for the value of
:
= 
= 

Solve for
:





16. After you have the value
use it to find the <u>actual</u> measurements of both
and
, by applying
to the following expressions from both
and
and solve them:
-The value of
:

-Solve for
:
= 


-The <u>actual</u> measurement of
:
= 
-Solve for
:




-The <u>actual</u> measurement of
: (if needed)
= 
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17. The two following angles, which is
and
are <u>Alternate Interior Angles</u> .Write an expression by using the following measurements from
and
. Then, solve the expression for the value of
:
= 
= 

-Solve for
:





18. After you have the value
use it to find the <u>actual</u> measurement of
, by applying
to the expression from
and solve it and find the actual measurement of an angle that is not labeled, which is
:
-The value of
:

Solve for
:
= 



-The <u>actual</u> measurement of
:
= 
-Since both
and
are supplementary (two angles that equals to
), and you want to find the <u>actual</u> measurement of
, Use the measurement of
and subtract it from
:


-The <u>actual</u> measurement of
:
= 