A Student Writes An Incorrect Step While Checking If The Sum Of The Measures Of 1

A student writes an incorrect step while checking if the sum of the measures of the two remote interior angles of triangle ABC below is equal to the measure of the exterior angle.Step 1: m∠x + m∠y + m∠z = 90 degrees (sum of adjacent angles) Step 2: m∠w + m∠z = 180 degrees (supplementary angles) Step 3: Therefore, m∠x + m∠y + m∠z = m∠w + m∠z Step 4: So, m∠x + m∠y = m∠w