The boundary point is? The solutions are all values ? 3

Ineed if you could explain and give me the answer you! this needs done

40) linda was making chocolate truffles for the first day of school. the recipe for 20 chocolate truffles is: i cup of cream 2 cups of dark chocolate she noticed this will not be enough truffles for the 42 sure that all students in each homeroom next year. to be sure that all students receive a truffle, linda must adjust her recipe. a. complete the recipe for 42 truffles cups of cream - cups of dark chocolate work:

Which of the following statements is true? a. sin 18° = cos 72° b. sin 55° = cos 55° с. sin 72° = cos 18° d. bоth a and c.