Respuesta :
Answer: 6.2 feet.
Step-by-step explanation:
1. You can make a triangle as you can see in the figure attached, where [tex]x[/tex] is the distance between the base of the ladder and the base of the building
2. To solve this problem you can apply the following proccedure:
[tex]cos(\alpha)=\frac{adjacent}{hypotenuse}[/tex]
Where [tex]\alpha=72degrees\\adjacent=x\\hypotenuse=20[/tex]
3. Substitute values:
[tex]cos(72)=\frac{x}{20}\\x=(20)(cos(72))\\x=6.2[/tex]

Answer:
6.2 feet
Step-by-step explanation:
A ladder is placed next to a building which will form a right angled triangle where,
ladder = the hypotenuse,
building = perpendicular; and
distance on the ground between the building and the ladder = base
We know the hypotenuse and the angle formed between the ladder and the ground to be 72°, so we can use the formula for Cos to find the base:
Cos = Base / Hypotenuse
Supposing x to be the base:
Cos (72°) =  x / 20
x = cos (72°) * 20
x = 6.2 feet
Therefore, the base is the ladder is 6.2 feet far from the base of the building.