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It is known that a (0, - 4), B (- 2,0) C (3,0) are the three vertices of △ ABC. A straight line L passing through the coordinate origin o intersects the line segment AB at point D, and the bisector of ∠ ADO and ∠ ABO intersects at point M?
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In the triangle ABC, ab = BC, D, e. f are the middle points of the edges BC, AC, AB respectively. Prove that the quadrilateral bdef is a diamond. If AB = 12, find the perimeter of the diamond bdef
E.f.d AC.AB.BC The midpoint of
The EF is parallel and equal to 1 / 2BC
∵BD=1/2BC
∴EF∥1/2BC
Ψ BD ‖ and = 1 / 2BC
Ψ EF ‖ and = BD
A quadrilateral bdef is a parallelogram
In the same way, it can be concluded that ED ‖ is equal to BF
And ∵ AB = BC
∴ED=EF
The quadrilateral bdeef is a diamond
∵AB=12
∴ED=6
The length of diamond shaped bdef = 6x4 = 24
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