[net.puzzle] Geometry Puzzle 5

gupta@asgb.UUCP (07/26/84)

>Once again, I have another problem, although could be one of the last.  Here
>goes:  In the obtuse triangle ABC (angle C is obtuse), point M is on AB such
>that AM = MB, point D is on BC such that MD is prpndclr to BC, and point E
>is a point on ME such that EC is prpndclr to BC.  Given the area of triangle
>ABC is 24, then find area of triangle BED.  Good luck!
>Billy Pizer
Correction>
>E is a point on MA such that EC is perpendicular to BC.
Solution>
As M is the mid-point of AB,
	area(MCB) = area(MCA) = 1/2 area(ABC) = 12     ... (1)
Also,
	area(DMC) = area(DME)                          ... (2)
    because they are on the same base (DM) and
    have the same height (DM is parallel to CE).
Now,
	area(MCB) = area(MDB) + area(DMC)
		  = area(MDB) + area(DME)  ... (from 2)
		  = area(BED)

	.
       . .  area(BED) = 12       ... (from 1)

Yogesh Gupta

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