Data Suff - Triangles

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Data Suff - Triangles

by ReenaMo » Wed Aug 20, 2008 4:17 pm
In the figure, L1 || L2. What is the area of Triangle ADC?

1. AD = 9
2. BE x AC = 24


Image


Sorry, you probably have to enlarge the figure to see it clearly. Can someone explain the methodology behind this one? The correct answer according to the Kaplan 800 book is (B), but I thought it was (E) because the Statement 2 does not tell you the area of Triangle ADC, only ABC, correct?

Thanks in advance!
Source: — Data Sufficiency |

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by parallel_chase » Wed Aug 20, 2008 4:50 pm
Statement II

Area of ADC = 1/2 * height * AC

Height = BE since L1 ll L2 (This is the only part which is hard to identify).

BE*AC = 24

BE = 24/AC

Area of ADC = 1/2 * BE * AC

=1/2 * 24/AC * AC = 12

Hence the answer is B.

Hope this helps.

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by sharmavivek » Thu Aug 21, 2008 3:31 am
There is an identity which says:
Any two traingles with same base and between same parallel line are equal in area.So Area of ADC = Area of ABC.[Its easy to find area of ABC]

Just to add to this one:
There is one more identity, which says if a quadilateral and a Traingle have same base and are between same parallel line then the area of Traingle is = Half the area of quadilateral.

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by sharmavivek » Thu Aug 21, 2008 3:32 am
There is an identity which says:
Any two traingles with same base and between same parallel line are equal in area.So Area of ADC = Area of ABC.[Its easy to find area of ABC]

Just to add to this one:
There is one more identity, which says if a quadilateral and a Traingle have same base and are between same parallel line then the area of Traingle is = Half the area of quadilateral.