Question

A 5m long ladder leans against a wall, with the top of the ladder being 4m above the ground. What is the approximate angle that the ladder makes with the ground?

Answer 1

53 degrees

Explanation:

There is an assumption that the ground is horizontal, so the ladder `(5m)` is the hypotenuse of a `3, 4, 5` triangle.

The height of the top of the ladder `(4m)` is opposite the angle asked for (let's call it `x`) so `sin(x)= 4/5`

so `x = sin^-1(4/5) = sin^-1(0.8) = 53.13(2dp) deg`

But we are asked for the approximate angle, so it's better to round the answer to 53 degrees.