Answer:
(a) 27 degrees (nearest degree)
(b) 17.9 m (to one decimal place)
Explanation:
Wow, that's along ladder, perhaps for the firemen!
From diagram,
(a)
sin(x) = 9 / 20 = 0.45
x = arcsin(0.45) = 26.74 degrees
(b)
height of wall ladder reaches
h = 20*cos(x) = 20*cos(26.74) = 17.86 m