Step-by-step explanation:
to find height :
draw a height from A to CD
height = (13) 2 - 5) 2 = 12 Cm
area = 10+20 /2 X 12= 180 cm 2
9514 1404 393
Answer:
a8 = 4
Put 8 where n is and do the arithmetic.
a8 = (1/2)(8) = 8/2 = 4
The 8th term of this arithmetic sequence is 4.
