Answer:
15.

16.
=

=
(if needed)
-------------------------------------------------------------------
17.

18.
=

Explanation:
15. The two following angles, which is
and
, are Corresponding Angles. 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 actual measurements of both
and
, by applying
to the following expressions from both
and
and solve them:
-The value of
:

-Solve for
:
=



-The actual measurement of
:
=

-Solve for
:




-The actual measurement of
: (if needed)
=

----------------------------------------------------------------------------
17. The two following angles, which is
and
are Alternate Interior Angles .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 actual 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 actual measurement of
:
=

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


-The actual measurement of
:
=
