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Similar triangles
1.
In ∆ABC, DE is parallel to side BC. Find the length of DE if
AD = 8, BD = 3 and BC = 12.
2.
In triangle ABC, ∠B = ∠FEA. Find the length of EF if AF = 9, AC = 15 and BC =
18.
3.
In ∆ABC, ∠B = ∠DAC. Prove that AC is the geometric
mean between CB and CD (AC2 = CB·CD).
4.
∆ABC and ∆ACD have a common side AC. E is any point on AC. EF
|| BC and EG || CD. Prove that
(1) ∆AFG is similar to ∆ABD
(2) ∆EFG is similar to ∆CBD
5.
AC is parallel to DB. AB and CD meet at O. Line segment through O intersect AC
and BD at E and F respectively. Prove that
OE / OF = AC / BD
