ABCD is a trapezium in which AB║DC, BD is a diagonal
and E is the mid-point of AD. A line is drawn through E
parallel to AB intersecting BC at F (see figure ).
Show that F is the mid-point of BC.
Answers
you can prove it by mid and converse of mid point theorem
Given ABCD is a trapezium.
We have to prove, F is the mid point of BC, i.e., BF=CF
Let EF intersect DB at G.
In ΔABD E is the mid point of AD and EG∣∣AB.
∴ G will be the mid-point of DB.
Now EF∣∣AB and AB∣∣CD
∴ EF∣∣CD
∴ In ΔBCD, GF∣∣CD
⇒ F is the mid point of BC.
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Trapezium:
A quadrilateral in which one pair of opposite sides are parallel is called a trapezium.
Converse of mid-point theorem:
The line drawn through the midpoint of one side of a triangle, parallel to another side bisects the third side.
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Given: ABCD is a trapezium where AB ∥ DC E is the mid-point of AD, i.e., AE = DE & EF ∥ AB
To prove: F is mid-point of BC, i.e., BF = CF
Proof: Let EF intersect DB at G.
In ∆ ABD
E is the mid-point of AD
EG ∥ AB
∴ G is the mid-point of DB
Given EF ∥ AB and AB ∥ CD,
∴ EF ∥ CD
In ΔBCD
G is the mid-point of BD
GF ∥ CD
∴ F is the mid-point of BC
Hence proved