Answer: 90° , 60° and 30° .
Step-by-step explanation:
Given : In a right triangle with a leg of 4 units and a hypotenuse of 8 units.
One angle should be 90°. (A right triangle has a 90° angle.)
Let the given leg is the side opposite to the angle
in the triangle.
Then by trigonometry , we have
[Sine of an angle is the ration of the side opposite to the angle and the hypotenuse of a right triangle.]
Also , 

Let x be the measure of the third angle.
BY Angle sum property of triangle , we have

Therefore , the measures of all angles in the triangle : 90° , 60° and 30° .