I am not quite sure what the question asks for,
But this is what i assume it wants:
Cos A= 0.6489
In this given one, we basically find the size of the angle A
we do cosine inverse on both sides to get the size of the angle A

: It looks like this in the calculator

× cos A=

(0.6489)
(

and cos cancels out)
A=

(0.6489)
A=49.54°
check:
cos 49.54=0.6489 (its right!)
Answer:
4_5=_1 then -1 is <25 25_1 25<-1
Answer:
23.6
Step-by-step explanation:
<u><em>Finding AC:</em></u>
Cos 61 = 
0.48 × 10 = Adjacent
AC = 4.8
<u><em>Now, CB:</em></u>
Cos 29 = 
0.87 × 10 = CB
CB = 8.8
<u><em>The perimeter:</em></u>
=> 10+4.8+8.8
=> 23.6