Answer:
4.9 feet
Step-by-step explanation:
First, we need to determine the height of the building using the following:

Where
H = Height of the building
L = Length of the first ladder = 20ft
B = Distance from the base of the building = 10ft
So, we have:





Next, is to determine the distance of the new ladder from the base of the building (B) using Pythagoras theorem using:

Where
--- Length of the second ladder
----- Height of the building
So, we have:




Solving for B2, we have:


Answer:
B. 21.64
Step-by-step explanation:
We have been given a triangle and we are asked to find the length of AC (b).
We will use law of cosines to find the length of side AC.

Upon substituting our given values in the formula we will get,
Upon taking square root of both sides of our equation we will be get,
Therefore, the length of b is 21.64 and option B is the correct choice.
The feet of cloth that she should buy for the capes is 4 feet.
<h3>
How many feet should she buy?</h3>
The mathematical operations that would be used to determine the answer are addition and multiplication.
Addition is the process of summing two or more numbers together. Multiplication is the process of determining the product of two or more numbers.
The first step is to convert yard to feet
According to the unit of conversion : 1 yard = 3 feet
1 x 3 = 3 feet
The second step is to add the feet needed for Akira's cape with the foot needed for the puppy's cape
Total feet needed = 3 + 1 = 4 feet
To learn more about addition, please check: brainly.com/question/349488
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