To find the measure of angle \( yvz \) using the numbers 39, 86, and 28, we assume that you are perhaps referring to the angles of a triangle, where 39, 86, and 28 are likely the angles.
If these are indeed the angles of a triangle, we should first ensure that they sum to \( 180^\circ \) (the sum of angles in any triangle must equal \( 180^\circ \)).
Calculating the sum:
\[ 39 + 86 + 28 = 153 \]
Since this does not equal \( 180^\circ \), it seems that the provided numbers are not the angles of a triangle.
If, instead, you mean to determine which angle out of those given corresponds to \( yvz \), please specify how \( yvz \) relates to the numbers or provide additional context regarding the geometry being referenced.
If you provide more details, I can help you further!