Answer :
Unfortunately, you haven't provided enough info. Could you possibly attach a sketch or photo image of this problem? What do you mean by 8_7?
What do you know about angle R? If this is one angle of a triangle, do you know the lengths of the opposite side, the adjacent side, the hypotenuse?
If so, share that info.
What do you know about angle R? If this is one angle of a triangle, do you know the lengths of the opposite side, the adjacent side, the hypotenuse?
If so, share that info.