Loading [MathJax]/jax/output/SVG/jax.js
 
+0  
 
0
1
2
avatar+833 

In pentagon ABCDE, \overline{AC} bisects \angle BCE and ¯AD bisects BDE. If CBD=30 and CED=60, then find CAD, in degrees.

 May 29, 2025
 #2
avatar+15088 
+1

Find CAD in degrees.

Thanks webbinsight for the useful suggestions to solve this tricky task!

 

ADB=ADE=αACB=ACE=β

The angles intersection AD/EC are twice:

(120°α) and (60°+α)

The angles intersection AC/BD are twice:

(30°+β) and (150°β)CAD=60°+αβ

In the triangle (intersection AC/BD) - A-D the following applies:

α=180°(150°β)(60°+αβ)β=15°

The angles intersection BD/CE are twice:

(180°30°2β=120°) and (60°)

In the triangle (intersection AD/CE) -  (intersection CE/BD) - D the following applies:

(120°)+(60°+α)+(α)=180°α=0 ? ? ?

 

I ask everyone for help.

laugh !

 Jun 3, 2025
edited by asinus  Jun 3, 2025
edited by asinus  Jun 6, 2025

0 Online Users