Triangle abc is a right triangle and sin(53o) = . solve for x and round to the nearest whole number.

A diagram would be nice.  If this is a right triangle, and one acute angle is 53 deg, then the other is 37 deg.  You don't specify any dimensions, so all you can do is use theoretical values here.

If x is opposite the 53 deg angle, and the length of the hypotenuse is h, then side x has length h(sin 53 deg) = 0.799h.