explsin mid point theorum
Answers
Answer:
The Midpoint Theorem states that the line segment joining the midpoints of any two sides of a triangle is parallel to the third side and equal to half of the third side.
Answer:
Step-by-step explanation:
Statement- The line segments joining the mid-points of any two sides are parallel to the third side and half of it.
Given- In triangle ABC, D and E are the mid-points of AB and AC respectively.
AD=DE and AE=EC
To prove- (i) DE is parallel to BC
(ii) DE=1/2BC
Construction- Produce DE up to F such that CF is parallel to AB
Proof-
(i) In triangle ADE and triangle FCE,
AE=CE (given)
Angle EAD=Angle ECF (alternate interior angles)
Angle AED=Angle FEC (vertically opposite angles)
By ASA congruence rule,
Triangle ADE is congruent to Triangle FEC
DE=EF
AD=CF
AD=DB
DB=CF
DB is parallel to CF
Hence, BCDF is a parallelogram.
(ii) DF=BC
DE+EF=BC
DE+DE=BC
2*DE=BC
DE=1/2BC
Hence, proved//