How high up the wall does the ladder reach is 17.21 ft.
To solve the question, we need to know what right-angled triangles are.
A right-angled triangle is a triangle in which the angle facing the longest side is 90°.
The ladder, the ground and the wall form a right angled triangle with hyptenuse side, length of ladder, L and opposite side to angle between ground and ladder, Ф = 73° is h. Opposite side equals height of ladder along wall, h.
From trigonometric ratios
sinФ = h/L
h = LsinФ
Substituting the values of the variables into the equation, we have
h = LsinФ
h = 18 ft × sin73°
h = 18 ft × 0.9563
h = 17.21 ft
So, how high up the wall does the ladder reach is 17.21 ft.
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