Which one of them is cuter?

Which of these is a consistent periodic pulse separated into equivalent intervals of time?

How did brunelleschi solve his problem with the dome of the florence cathedral? a. he created an outer support shell. b. he created many layers of support within the dome. c. he created external supports for the dome. d. all of the above

1× 10×10×10+2×30×30=[tex]1 \times 10(4) + 2 \times 10(3) = \\ [/tex]