My Math Forum  

Go Back   My Math Forum > High School Math Forum > Geometry

Geometry Geometry Math Forum

Thanks Tree2Thanks
  • 2 Post By skipjack
LinkBack Thread Tools Display Modes
June 6th, 2019, 08:17 PM   #1
Joined: Jun 2019
From: New York

Posts: 2
Thanks: 0

Help with proof?

The givens are,
Quad ABCD is inscribed inside the circle
Diagonals AC and BD meet at point E.
Line AD is congruent to Line CD

How do you prove that
BE * AD = EC * AB?
Attached Images
File Type: jpg 15598809819581306921796.jpg (82.7 KB, 11 views)
Sakkara is offline  
June 7th, 2019, 12:49 AM   #2
Global Moderator
Joined: Dec 2006

Posts: 20,969
Thanks: 2219

$\small\angle$ADB = $\small\angle$ACB = $\small\angle$ECB and $\small\angle$ABD = $\small\angle$DBC = $\small\angle$EBC.
AB/AD = sin($\small\angle$ADB)/sin($\small\angle$ABD) = sin($\small\angle$ECB)/sin($\small\angle$EBC) = BE/EC.
Thanks from topsquark and Sakkara
skipjack is offline  

  My Math Forum > High School Math Forum > Geometry


Thread Tools
Display Modes

Copyright © 2019 My Math Forum. All rights reserved.