Melissa has started training for a race. The first time she trains, she bikes 5 miles. Each subsequent time she trains, she bikes 0.5 mile farther than she did the previous time. A. Use summation notation to write an arithmetic series to represent the total distance Melissa has biked after she has trained n times.

B. Use the formula for a partial sum of the series you wrote in part a, above, to answer this question: What is the least number of times Melissa must bike for her total distance biked during training to exceed 60 miles?

Okay so for every triangle has three angles that always add up to 180 degrees. and to tell the difference between whether they are secure, right or obtuse is that acute: has one angle that is less than 90 degrees. right triangle means there is at least one angle that is exactly 90 degrees. and an obtuse angle has an angle that is bigger than 180 degrees. i’ll do #13 as an example: 13. 40 and 50 so if every triangle has 180 degrees 40+50= 90 degrees then180-90= 90 degrees so the third angle is 90 degrees and because this triangle has a 90 degree angle it means it is a right triangle