One side of a roof is in the shape of a trapezoid (similar to the one on Pizza Hut). The top row requires 10 shingles, the secon
d row requires 16 shingles, the third row requires 22, etc. The nth row on the bottom requires 6n + 4 shingles. What is the total number of shingles needed to cover this side of the roof ? A) n2 + 6n
b) 3n2 + 7n
C) 6n2 + 10
D) 6n2 + 14n
This is an arithmetic sequence and the sum of n terms is -->
n/2(2a+(n-1)d), where a is the first term and d is the common
difference. In this case a = 10, d =6
