Intersection 81017

There are also two equilateral triangles ABC, and BDE, such that the size of the angle ABD is greater than 120° and less than 180° points C and E lie in the same half-plane defined by the line AD. The intersection of CD and AE is marked F. Determine the size of angle AFD.

Correct answer:

AFD =  120 °

Step-by-step explanation:

EAB=BDC=x CBE=y ABX = BYD= CYE = CXE = 180  60 x = 120x EXB = CYB = 60+x AEB = 180x(60+y) = 120xy   Δ AEB: AB=BE x=(120xy) x=120xy y = 1202x  XFYB: 60+x+(60+x)+y+AFD = 360 60+x+(60+x)+ 1202x+AFD = 360 120+2x+ 1202x+AFD = 360  AFD=AFD=360120120=120



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