Answer:
(.2)(15.75)=3.15
Step-by-step explanation:
An=a1+d(n-1)
a1=first term
d=common difference
n=which term
common difference is 5 first term is 2
an=5+2(n-1)
19th term is n=19
a19=5+2(19-1)
a19=5+2(18)
a19=5+36
a19=41
19th term is 41
For a triangle to be a triangle all the angles have to add up to 180 degrees. So 52 degrees plus 28 degrees would equal 80. So now to find the answer 180 - 80 then your final answer is 100! Hope This Helps
Square root(27)= 5.19615242271
or you can round if needed to 5.20