Which of the following is not a special triangle a.) 60-60-60 triangle b.) 20-60-100 triangle c.) 45-45-90 triangle d.) 30-60-90 triangle

The answer should be B

The recursive form is very useful when there aren't too many terms in the sequence. For instance, it would be fairly easy to find the 5th term of a sequence recursively, but the closed form might be better for the 100th term. On the other hand, finding the closed form can be very difficult, depending on the sequence. With computers or graphing calculators, the 100th term can be found quickly recursively