Line a and Line b are parallel.
∠x = 34° (alternative angles on a parallel line are equal)
Answer: ∠x = 34° (option C)
The first one can be done by Pythagoras theorem such as

then

then

The second one can also done by Pythagoras theorem, note that this is isosceles triangle so

, again by using Pythagoras theorem

then

then

For the last one can also done by property of 30-60-90 triangle.

Answer:
where is the angle
Step-by-step explanation:
7mn³(5n+2m⁵) is the factorisation.