Answer:
≈ 35.1 ft
Step-by-step explanation:
The model is a right triangle with ladder being the hypotenuse and the angle between the ground and the ladder is 70°
Using the cosine ratio, with l being the length of the ladder.
cos70° = [tex]\frac{adjacent}{hypotenuse}[/tex] = [tex]\frac{12}{l}[/tex] ( multiply both sides by l )
l × cos70° = 12 ( divide both sides by cos70° )
l = [tex]\frac{12}{cos70}[/tex] ≈ 35.1 ( to the nearest tenth )
The ladder is approx 35.1 ft long