9000151301

SubArea: 
Plane geometry
Level: 
B
Project ID: 
9000151301
Source Problem: 
2010014609
Accepted: 
1
Clonable: 
1
Easy: 
0
Find the angle \(\varphi \) between the lines \(3x - 7 = 0\) and \(x + y + 13 = 0\).
\(45^{\circ }\)
\(90^{\circ }\)
\(60^{\circ }\)
\(30^{\circ }\)