Grades 7-8 Video Solutions 2026-2026_7-8

Video Transcription

Video Summary

Ethan’s figure implies \( \angle EDA = 3x\) and \( \angle BAD = 2x\). Since \(EA = ED\), triangle \(AED\) is isosceles, so the other two angles are equal. Also, \( \angle AED = \angle ADC\), and with \(AD \parallel BC\) and \(AB = CD\), quadrilateral \(ABCD\) is an isosceles trapezoid, making the base angles equal.  

Using triangle angle sum in \(AED\):  
\(3x + 3x + 2x = 180\), so \(8x = 180\) and \(x = 22.5\).  

Thus the relevant angle is \(135^\circ\).  
<strong>Answer: \(135^\circ\).</strong>

Keywords

isosceles trapezoid

triangle angle sum

base angles

isosceles triangle

geometry problem