9000151308

Level: 
Project ID: 
9000151308
Source Problem: 
Accepted: 
1
Clonable: 
1
Easy: 
0
Given points \(A = [-1;4]\), \(B = [2,-2]\) and \(C = [5,-1]\), find the angle \(\beta \) (the interior angle at the vertex \(B\)) in the triangle \(ABC\).
\(98^{\circ }08'\)
\(81^{\circ }53'\)
\(76^{\circ }17'\)
\(68^{\circ }27'\)