Angle C is inscribed in circle O. AB is a diameter of circle O.

What is the measure of A?

60

Element 17 is chlorine it is a group 7 element(halogen) and belongs to period 3 of the periodic table

1. 0.3 •4 is the same as 4 groups of 0.32. 7•0.8 is the same as 7 groups of 0.83. it increases by 0.5 every time, so 0.5x4 it increases by 0.9 every time, so 0.9x5. 0.9•12=10.86. 0.47•5=2.35i can finish the next ones in a separate post