The triangle is given with angles, 30, 60 and 90 degrees. Since only one side is given, we shall find the other two sides one after the other by applying the Trigonometry ratios.
Using the angle30 as the reference angle,
Sin 30 = Opposite/ Hypotenuse
Note that the hypotenuse (longest side) has been provided as 8, and the opposite is the side facing the reference angle. Since we have chosen 30 as the reference angle, the side facing angle 30 shall be the opposite.
Sin 30 = Opposite/8
By cross multiplying you now have,
Sin 30 * 8 = Opposite
By use of calculator, Sin 30 equals 0.5
0.5 * 8 = Opposite
4 = Opposite
Now that two of the sides have been calculated, we can further calculate the third side by either use of Pythagoras theorem or the Trigonometry ratios
The Triangle now has three angles named and two sides named as follows;
Sin 60 = Opposite/Hypotenuse
Sin 60 = Opposite/8
Sin 60 in the calculator is given as 0.8660
0.8660 * 8 = Opposite
6.928 = Opposite
Opposite is approximately 7 units