Answer:
144°
Step-by-step explanation:
step 1
Find the measure of the central angle of the regular pentagon
Divide 360 degrees by 5 (the number of sides)

Let
c----> the center of the pentagon
we know that
m∠ECA=72°
m∠ACB=72°
therefore
m∠ECB=m∠ECA+m∠ACB
substitute the values
m∠ECB=72°+72°=144°
The measure of angle ECB is equal to the degrees that the pentagon rotate
Scientific notation is the representation of a number in a power of ten, with a sequence of digits placing the comma after the first digit, and the power or then that is mathematically consistent with the number. For example 400 is 4.00 * 10^2; 3100 is 3.100 * 10^4; 13421 = 1.3421 * 10 ^4. It is important that you have only one digit before the comma. So, 5,098,00 is 5.098 * 1,000,00 = 5.098 * 10^6. <span>The answer is the option c. 5.098 * 10^6.</span>
Answer:
x = -7/4, 3
Step-by-step explanation:
Use quadratic formula
The circumference = π x the diameter of the circle (Pi multiplied by the diameter of the circle). Simply divide the circumference by π and you will have the length of the diameter. The diameter is just the radius times two, so divide the diameter by two and you will have the radius of the circle