Question

If vector |a| = 12 cm, |b| = 13 cm, and the angle between them when placed tail to tail is 35°, find a • b to the nearest centimetre
a)
a • b = 57
b)
a • b = 8
c)
a • b = 11
d)
a • b = 24

Answer 1

Tail to tail, the dot product is
12 * 13 cos 35 = 127.78 cm^2
Round that off as requested. It is an area, not a length.