If <span class="math-tex">\(\vec a, \vec b, \vec c\)</span> are vectors such that <span class="math-tex">\(\vec a + \vec b + \vec c = 0\)</span> and <span class="math-tex">\(|\vec a| = 7, |\vec b| = 5, |\vec c| = 3\)</span>, then the angle between the vectors <span class="math-tex">\(\vec b\)</span> and <span class="math-tex">\(\vec c\)</span> is?
Step-by-step Solution:
Move b and c in one side and take square on both side