If DE = EF, then what is the measure of angle CEF?

Graph the equationy=x^2 -[tex]y = x^{2} - 2[/tex]

Ijust need these 2 questions answered (the second pic is just confirmation i'm not confident in that answer)

You can ride your bike around your block 6 times and the whole neighborhood 5 times in 16 minutes. you can ride your bike around your block 3 times and the whole neighborhood 10 times in 23 minutes. how long does it take you to ride around the neighborhood?