Respuesta :
Answer:
answer is:
16 feet.
Step-by-step explanation:
We are given that:
The base of a 20-foot ladder is placed 12 feet from a building.
Now we re asked to find how far up on the building does the ladder reach?
i.e. we can consider a right angled triangle such that the base is given to be 12 feet.
the length of hypotenuse is given to be= 20 feet.
Now we are asked to find the height of a right angled triangle.
Let us consider ΔABC.
such that ∠B=90°, BC=12 feet, AC=20 feet
Now we can use pythagorean theorem to find out the length of side AB.
[tex]AC^{2}=AB^{2}+ BC^{2}\\\\AB^{2}=AC^{2}-BC^2\\\\AB^2=(20)^2-(12)^2\\\\AB^2=400-144\\\\AB^2=256\\\\AB=16[/tex]
Hence, ladder is 16 feet above the ground level.