calculate the area, side a, larger and smaller diagonal of a regular hexagon if the radius of the circumscribed circle is R = 4cm help, please

Aculture started with 3000 bacteria. after 5 hours it grew to 3900 bacteria. predict how many bacteria will be present after 9 hours

In the sixth grade 13 out of 20 students have a dog if there are 152 sixth grade students how many of them have a dog

The figure shows triangle def and line segment bc, which is parallel to ef: triangle def has a point b on side de and point c on side df. the line bc is parallel to the line ef. part a: is triangle def similar to triangle dbc? explain using what you know about triangle similarity. part b: which line segment on triangle dbc corresponds to line segment ef? explain your answer. part c: which angle on triangle dbc corresponds to angle f? explain your answer. asap