Answer:
(a) 27°
(b) 17.9m
Step-by-step explanation:
According to the attachment
⠀
let AB be the ladder
BC be the distance between the ladder and wall
⠀
(a) We have to find ∠A by trigonometry formula
[tex] \sf \sin A = \frac{perpendicular}{hypotenuse} [/tex]
Here angle A is facing BC so it is perpendicular
and AB is the longest side so it is hypotenuse
[tex] \sf \implies \sin A = \frac{BC}{AB} \\ \\ \\ \sf \implies \sin A = \frac{9}{20} \\ \\ \\ \sf \implies \sin A = 0.45 \\ \\ \\ \sf \implies \sin A = \sin27{ \degree} \\ \\ \\ \sf \purple {A = 27{ \degree}}[/tex]
(b)
AC is the distance from the upper end of the ladder to ground
we will find it by Pythagoras theorem
[tex] \sf {hypotenuse}^{2} = {perpendicular}^{2} + {base}^{2} \\ \\ \\ \sf \implies {AB}^{2} = {BC}^{2} + {AC}^{2} \\ \\ \\ \sf \implies {20}^{2} = {9}^{2} + {AC}^{2} \\ \\ \\ \sf \implies 400 = 81 + {AC}^{2} \\ \\ \\ \sf \implies 400 - 81 = {AC}^{2} \\ \\ \\ \sf \implies 319 = {AC}^{2} \\ \\ \\ \sf \implies \sqrt{319} = AC \\ \\ \\ \sf \blue{\implies 17.86 = AC}[/tex]
