For triangle abc angle a = 35 angle b = 55 and side c = 70 find side b to the nearest whole number

It's an right triangle because it has an angle with 90º.

A=35º

B=55º

A+B+C=180º

35º+55º+C=180º

C=180º-35º-55º

C=90º

We have in this triangle:

B=55º

b=opposite (whith respect to angle B)

c=hypotenuse (because it's in front of the right angle)

sin Ф = opposite / hypotenuse

In this case:

sin 55=b/70

b=70 (sin 55º)

b=57.34 ... ≈57

answer: the length of the side b would be 57 u (u=units of lengths)