BASIC PROPORTIONALITY THEOREM. In a triangle, a line drawn parallel to one side, to intersect the
other sides in distinct points, divides the two sides in the same ratio,
Cornerom BASIC PROPORTIONALITY THEODEM I line divide any two sides of a triangle
Answers
Answer:
this question is of which type in the class I will give you the answer with full step by step explanation and for your information it is not mathematics it is physics or chemistry mention the subject properly.
hi mate,
PROOF OF BPT
Given: In ΔABC, DE is parallel to BC
Line DE intersects sides AB and AC in points D and E respectively.
To Prove:
AD AE
----- = -----
DB AC
Construction: Draw EF ⟂ AD and DG⟂ AE and join the segments BE and CD.
Proof:
Area of Triangle= ½ × base × height
In ΔADE and ΔBDE,
Ar(ADE) ½ ×AD×EF AD
----------- = ------------------ = ------ .....(1)
Ar(DBE) ½ ×DB×EF DB
In ΔADE and ΔCDE,
Ar(ADE) ½×AE×DG AE
------------ = --------------- = ------ ........(2)
Ar(ECD) ½×EC×DG EC
Note that ΔDBE and ΔECD have a common base DE and lie between the same parallels DE and BC. Also, we know that triangles having the same base and lying between the same parallels are equal in area.
So, we can say that
Ar(ΔDBE)=Ar(ΔECD)
Therefore,
A(ΔADE) A(ΔADE)
------------- = ---------------
A(ΔBDE) A(ΔCDE)
Therefore,
AD AE
----- = -----
DB AC
Hence Proved.
i hope it helps you.