Aregular decagon is inscribed in a circle. radii are drawn from the center of the circle to two consecutive vertices of the dodecagon. what is the degree of the central angle?

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Carmen and matt are conducting different chemistry experiments in school. in both experiments, each student starts with an initial amount of water in a flask. they combine two chemicals which react to produce more water. carmen's experiment starts with 30 milliliters of water in a flask, and the water increases in volume by 8.5 milliliters per second. matt's experiment starts with 10 milliliters of water and increases in volume by 28% each second.