Answer:21 cm
Step-by-step explanation: The circle's circumference is 84 cm. 84 / 4 = 21. Therefore the length of the arc XY is 21 cm.
Answer:
91/4 or 22 3/4
Step-by-step explanation: i just know
ANSWER
The value of a and b are:

EXPLANATION
The expression given to us is

We square both sides of the equation to obtain

We now find the prime factorization of 648 to obtain,

We now compare the exponents on both sides of the equation to obtain,

Therefore the correct option is C
Answer: D
Step-by-step explanation: