Answer:
(A) x=40
Step-by-step explanation:
Given: It is given that m is parallel to n.
To find: The value of x.
Proof: It is given that m is parallel to n, from the figure it can be seen that 105° and (3x-15)° forms alternate exterior angles which are equal in measure because m is parallel to n.
Thus, 
⇒
⇒
⇒
⇒
Thus, the value of x is 40, hence option A is correct.
Answer:
Perimeter of the Triangle

Answer: A
Step-by-step explanation:

Actually Welcome to the Concept of the Equilateral Triangles.
Since, we know that, all the sides of a triangle are equal, hence it is a Equilateral triangle.
Equilateral triangle has one all angles equal to 60°.
so, major angle P = 60°
hence, 2x=60°
===> x = 30°