Angle C is inscribed in circle O. AB is a diameter of circle O. What is the radius of circle O?

When you answer this can you explain

Rob spent 25%, percent more time on his research project than he had planned. he spent an extra h hours on the project. which of the following expressions could represent the number of hours rob actually spent on the project? two answers

Aflower has 26 chromosomes. to create a new flower,how many would a sperm cell have what is called?