Which of the following best completes the proof showing that ΔWXZ ~ ΔXYZ? triangles WXZ and XYZ that share side XZ with right angle XZW, WZ equals 10, XZ equals 5, and YZ equals 2 and one half Since segment XZ is perpendicular to segment WY, angles WZX and XZY are both right angles and congruent. The proportion shows the corresponding sides are proportional, so the triangles are similar by the SAS Similarity Postulate.