Suppose a 20-foot ladder is leaning against a building, reaching to the bottom of a second-floor window 15 feet above the ground. what angle, in radians, does the ladder make with the ground round your answer to two decimal places

The answer is β=0,85 rads

Explanation:

As the ladder is leaning against the building, we can imagine there´s a triangle where 20ft is the hypotenuse and 15ft is the maximum vertical distance between the ladder and the ground, it means, the leg opposite to β which is the angle we need

Let β(betha) be the angle between the ladder and the ground

We also know that

In this case we will need to find β, this way:

Then β=48,6°  

We also have that 2πrads is equal to 360°, in this way we find how much β is in radians:

then we find β=0,85rads

the correct answer is b