Respuesta :

We are asked to find the angle B but not in degrees, in radians. To solve this, we need to remember the conversion of degrees to radians such as pi = 180° and 2pi = 360°. Solving cosB = 0.12, we have  the solution below:
cosB = 0.12 , perform inverse cosine such as:
B = inverse cos 0.12
B = 83.11°
converting B to radian, we have:
83.11° * (2pi radian / 360°) = 1.451 radians

The answer is 1.45 radians.