The correct answer to prove similarity in two triangles using the SAS (Side-Angle-Side) criterion is:
b. If two corresponding side lengths of each triangle are given and are proportional, with a proven included angle measure, the triangles are similar.
Here's a brief explanation of all the options:
a. This statement describes the SSS (Side-Side-Side) criterion for similarity, not SAS. If all three sides of two triangles are proportional, then the triangles are similar by SSS.
b. This accurately describes the SAS similarity criterion. If two sides of one triangle are in proportion to two sides of another triangle, and the included angle between those sides is congruent, then the triangles are similar.
c. This statement about using a scale factor is not a specific criterion for determining triangle similarity. While triangles might be similar if they are related by a specific scale factor, this does not directly use the SAS criterion.
d. This describes the AA (Angle-Angle) criterion for similarity. If two angles in one triangle are equal to two angles in another triangle, the triangles are similar.
So, option b is the best choice among the options given.