Step-by-step explanation:
Hey there!
Simply work with it.
As it is a Right angled triangle, taking angle 40° as a reference angle. Then,
Length of board = hypotenuse = 15 feet.
To find: height of ladder = perpendicular.
Now,
Taking sin ratio,
[tex] \sin = \frac{p}{h} [/tex]
[tex]sin \: 40 = \frac{p}{15} [/tex]
or, as in per the given sin value is 0.6428
so,
[tex]0.6428 = \frac{p}{15} [/tex]
or, 15 × 0.6428 = p
or, p = height of ladder = 9.642.
Therefore, p = height of ladder = 10 feet. { rounding off we get 10 feet as answer}.
Hope it helps...
