Page 3 - Mid Point Theorem lab activity

6. ∆ADE completely covers ∆EFC.

Observation
We observe that ∆ADE exacdy overlaps ∆EFC.
∴ ∠1 = ∠2 (corresponding angles)
AC is any transversal line intersecting the lines DE and BC.
∴ DE || BC.
By paper folding we observe that, in fig (iv) F, the mid point of BC coincides
with D.
∴ DE = FC (As DE superimposes on FC)
or DE = FC = BC2

Result
Hence, it is verified that the line joining the mid-points of two sides of a triangle
is parallel to third side and half of it.

Learning Outcome
Line segment joining the mid-points of any two sides of a triangle is parallel to
the third side and is equal to half of it. This is true for all types of triangles like
acute-angled triangle, obtuse-angled triangle and right-angled triangle.