O is the center of the circle shown, which has radius 18 cm. A, B, C and D are points of the same circle. If arc AB has a measure of 80 degrees, arc DC has a measure of 90 degrees, and arcs BC and AD have the same measure, then what is the length of arc BC?​

256π units²   (answer b)

step-by-step explanation:

the formula for the surface area of a sphere of radius r

is             a = 4πr²

and so, if r = 8 units, then the surface area is:

a = 4π(8 units)² = 256π units²   (answer b)

i think the answer is b.

step-by-step explanation:

not 100% sure though.

3. (5x + 1) - (-10x + 6)

simplify the answer choice. combine like terms. remember to distribute the negative to the terms inside the second parenthesis. also remember that two negatives = one positive, and one of each sign = negative.

- (-10x + 6) = + 10x - 6

simplify. combine like terms:

5x + 1 + 10x - 6

5x + 10x + 1 - 6

15x - 5

∴ it is your answer

~

answer: 7

step-by-step explanation: