With the meal costing $18 and the tip being $15 the total will be $33
To find the circumference of a circle you have to multiple the radius by 2 and also by pi. So, to find the radius when given just the circumference, who have to do the reverse operation and divide the circumference by 2 and also by pi to get the answer of 22.92993631, which you could of course round.
Answer:
The vertices are (-16,-5) and (14,-5)
The foci are (-26,-5) and (24,-5)
Please, see the attached file.
Thanks.