Answer:
The value of ∠4 is 45° .
Explanation:
Given that , ∠4 = x + 30 ° & ∠2 = 2x + 15 .We need to find the measure of ∠4 . So from the figure we can see that , ∠2 & ∠4 are corresponding angles .So they will be equal. 
⇒ ∠2 = ∠4 [ Corresponding angles ]
⇒ x + 30° = 2x + 15°
⇒ 2x - x = 30° - 15° 
⇒ x = 15° 
Hence the value of x is 15° 
⇒ ∠4 = x + 30° 
⇒ ∠4 = 15° + 30° 
⇒ ∠4 = 45° 
★ Hence the value of ∠4 is 45° .