Answer:
C. c^2=a^2+b^2-2abcos(90°)
Step-by-step explanation:
This is the law of cosine.
1 yard = 3 feet
Then the to find the number of feet in a number of yards use the conversion factor, 1 = 3 feet / yard
number of feet = number of yards * 3 feet/yard
If the number of feet is f and the number of yards is y, you can write the expression in this way:
f = 3y
The sum of the question is 5.