Question

What is the slope of the given slide?

Answer 1

$\text{Slope,~} \tan \theta =\dfrac{15}{18}=\dfrac 56$

Answer 2

Use Pythagoras theorem:
a^2 = b^2 + c^2
-15^2 + 18^2 = a^2
a^2 = 99
a = root of 99