In which triangle is the measure of the unknown angle, x, equal to the value of sin–1(StartFraction 5 Over 8. 3 EndFraction)? A right triangle is shown. The length of the hypotenuse is 8. 3 and the length of another side is 5. Angle x is between those sides. A right triangle is shown. The length of the hypotenuse is 8. 3 and the length of another side is 5. Angle x is opposite to side with length 5. A right triangle is shown. The length of the hypotenuse is 5 and the length of another side is 8. 3. The angle opposite to side with length 8. 3 is x. A right triangle is shown. The length of 2 sides are 8. 3 and 5. The angle opposite to side with length 5 is x.