Answer:
Measure of Angle 5 = 150 degree.
Explanation:
Given line g and h are parallel lines.
Let angle measuring
be a.
From figure we can see that
both are Linear Pair Postulate,
i.e.
![\angle\ a+\angle 3 =180\ degree](https://img.qammunity.org/2020/formulas/mathematics/middle-school/5xzwsa3hp59ttneltfnw8xg459qdy68c3t.png)
So,
![30\ degree +\angle 3 =180\ degree](https://img.qammunity.org/2020/formulas/mathematics/middle-school/i6c9g08vyuq5fsdxhlt09g67kkrdlpbsem.png)
![\angle 3 = 180-30](https://img.qammunity.org/2020/formulas/mathematics/middle-school/djbxb9ebckbdsac8pq3y9wrk6tropv87jd.png)
------------(equation 1)
Now,
are alternate interior angles, and alternate interior angles are equal.
i.e.
![\angle\ a = \angle 4](https://img.qammunity.org/2020/formulas/mathematics/middle-school/o6ta2gtwrt56oanhdioykfhufebvxa5gq6.png)
Therefore
------------(equation 2)
Now,
both are Linear Pair Postulate,
i.e.
![\angle\ 4 +\angle\ 7 = 180\ degree](https://img.qammunity.org/2020/formulas/mathematics/middle-school/fookxvp9zgf0w5b2154ptubjkw7atm1rwg.png)
------------------(from equation 2)
![\angle\ 7 =180-30](https://img.qammunity.org/2020/formulas/mathematics/middle-school/mphcc6c3pddtd5sb395xu4degfhg4jsrv0.png)
---------(equation 3)
Now,
are vertically opposite angles, and vertically opposite angles are equal.
So,
![\angle 7=\angle 5](https://img.qammunity.org/2020/formulas/mathematics/middle-school/xmzzgcrizg8lj8ouwkkpribf0pghqemjo0.png)
-----------------(from equation 3)