Round to the given place value hundreds and tens 547 , 609 and 990

The ph level of a blueberry is 3.1 what is the hydrogen-ion concentration [h+] for the blueberry

Given: circle o, cd is diameter, chord ab || cd. arc ab = 74°, find arc ca.

(10. in the figure, a aabc is drawn tocircumscribe a circle of radius 3 cm ,such thatthe segments bd and dc are respectively oflength 6 cm and 9 cm. find the length ofsides ab and ac.