The magnitudes of mutually perpendicular forces

PHYSICS · Single correct · A Level · Physics · Mechanics and materials · Mechanics and materials

Problem

\mathbf{a}

\mathbf{b}

and

\mathbf{c}

are 2, 10 and 11 respectively. Then the magnitude of its resultant is (1) 12 (2) 15 (3) 9 (4) None of these