Find the angle between the given vectors to the nearest tenth of a degree. u = <8, 7>, v = <9, 7>?

u . v = ||u|| * ||v|| * cos(t)
8 * 9 + 7 * 7 = sqrt(8^2 + 7^2) * sqrt(9^2 + 7^2) * cos(t)
72 + 49 = sqrt(64 + 49) * sqrt(81 + 49) * cos(t)
121 = sqrt(113) * sqrt(130) * cos(t)
121 = sqrt(113 * 130) * cos(t)
121 / sqrt(113 * 130) = cos(t)
121 * sqrt(113 * 130) / (113 * 130) = cos(t)
121 * sqrt(11300 + 3390) / (11300 + 3390) = cos(t)
cos(t) = 121 * sqrt(14690) / 14690
t = arccos(121 * sqrt(14690) / 14690)
t = 3.3109415146114433670418872083861

3.3 degrees

Rule
u . v = ||u|| * ||v|| * cos(t)

u • v = ( 8i + 7 j ) • (9i + 7j )
u • v = 72 + 49 = 121
121 = √113 √130 cos ∅
cos ∅ = 1
∅ = 0 °