What is 10 g/cm³ a measure of

In the image, point a marks the center of the circle. which two lengths must form a ratio of 1 : 2? (options are in the images since thought they were harmful phrases)

List x1, x2, x3, x4 where xi is the midpoint endpoint of the five equal intervals used to estimate the area under the curve of f(x) between x = 0 and x = 10.

Aye asap pls ! markin da brainiest too ! btw da step choices are all add, distribute, divide, n subtract