In this figure, sin(a) = 2 3 What is the value of cos(b) ? A) 1 3 B) 2 3 C) 2 3 D) 3 2


\frac{2}{3}

The angles a and b sum to 90°, so they are complementary. A trigonometric identity asserts that cos(90° - a) = sin (a) for any angle a, so cos(b) = sin (a) = \frac{2}{3}.
*not asking just informing