Answer:
49.47
Step-by-step explanation:
Take what she started with and subtract what she ended with
428.25 - 378.78
49.47
This is the amount she spent
Since the only two corresponding side you have are 10 units and 4 units, you can divide these two numbers to get the scale factor.
10÷4=2.5
next you find the sides corresponding to X Y and Z and if it is on the bigger figure you divide, if it is on the smaller side you multiply
X corresponds with 5 (so ×2.5)
Y corresponds with 8 (÷2.5)
Z corresponds with 10 (÷2.5)
final answer is X=12.5 Y=3.2 Z=4
I try to explain the question and give the answer, I hope this helps!
For this problem you must do Pythagorean theorem:

In this example 10ft is c and 7ft is a (or it could be b, and you'll be solving for a instead of b. It's the same thing, since a and b are both legs)
Plug what you know into the equation:

49 +b^{2} = 100
Bring 49 to the right side by subtracting it:
b^{2} = 51
Now you still must isolate b. The opposite of squaring is taking the square root so take the square root of both sides to cancel it from the left side:

b = 7.1414
b ≈ 7 ft
Hope this helped!
Answer:
AB = 26.5º
Step-by-step explanation:
cosA = adj/hyp
cosA = AC/AB
cos41 = 20/AB
Multiply both sides by AB
AB * cos41 = 20
Divide both sides by cos41
AB = 20/cos41
AB = 26.5º