Proposed Problem
Click the figure below to see the complete problem 398 about Parallelogram, Area, Similarity, Congruence.
See also:
Complete Problem 398
Level: High School, SAT Prep, College geometry
Saturday, December 5, 2009
Problem 398: Parallelogram, Area, Similarity, Congruence
Labels:
area,
congruence,
parallelogram,
similarity,
triangle
Subscribe to:
Post Comments (Atom)
suggest to others
ReplyDeleteMN mark as x. Express EM and NC by x (thales theorem)
Express h1 (altitude EBC, or AFD) by h2 (altitude AECF)
(similar triangles)
Express S=s1+s2+s3 (s1 EBC, s2 AECF, s3 AFD)
Let S2= Area(BHDG)
ReplyDeleteWe have NG=HQ=2/3 *PD [Tri. AQH~Tri. APD]
NP=1/2* PD [Tri. DPF~ Tri. DNC]
So NG/NP=4/3
Calculate DG/NP= (PD+NP+NG)/NP= 2+1+4/3=13/3
S1/S2=Area(MNPQ)/Area(BHDG)=NP/GD =3/13 [Both para. have the same height]
S2/S= Area(BHDG)/Area(ABCD)= DH/DA=1/3 [Both para. have the same height]
So S1/S=1/13
Peter Tran
vstran@yahoo.com