- #1

- 1,421

- 5

"We next determine the magnitude of the centripetal centripetal (radial) acceleration, a

_{r}. Because CA in fig. 5-2a is perpendicular to V

_{1}, and CB is perpendicular to V

_{2}, it follows that the angle Δθ, defined as the angle between CA and CB, is also the angle between V

_{1}and V

_{2}. Hence the vectors V

_{1}, V

_{2}, and ΔV in fig. 5-2b form a triangle that is geometrically similar to the triangle CAB in fig. 5-2a"

I have attached the two figures. Why are the two triangles similar?