Step-by-step explanation:
Length of arc of a circle is given as:

Thus, the measure of central angle is 140°.
<span>Tractable refers to that how hard is problem
Tractable are those that can be solved in a polynomial time
where as the intractable are those which can be solved by using large time
whereas unsolvable are those which cannot be solved and requires infinite amount of time
hope it helps</span>
Answer:
Proved
Step-by-step explanation:
Figure two triangles which are congruent to each other has been attached
Proof :
1)BC= CD ( given )
2) AC= CE ( Given)
3) ∠ACB= ∠ECD ( vertically opposite to each other)
therefore, ΔABC≅ΔDCE ( By SSA postulate)
Now, CF and CG be medians on the sides Ab and DE of the Δ's ABC and DCE respectively
⇒CF= CG because of CPCTC that is corresponding parts of congruent triangles are congruent.
Therefore, congruent triangles have congruent corresponding medians.