Please write clearly and step by step Thank you so much Find

Please write clearly and step by step. Thank you so much!

Find the angle between the given vectors. Round to the nearest tenth of a degree, it necessity. 15) t = (-1, -6), s = (4, 5)

t=<-1,-6> , s=<4,5>

I t I =sqrt(1+36)=sqrt 36 , I s I = sqrt(16+25)=sqrt41

t.s= -1*4 + -6*5= -34

cos theta=t.s/(I t I I s I) =-34/sqrt(1476)

theta=cos^-1(-34/sqrt1476) = 152.2 degree