1. BC/CD = AC/CE 1. Given
2. <BCA is congruent to <ECD 2. Vertical angles are congruent
3. Tr.ACB is congr to Tr.ECD 3. SAS Similarity
Given:
Polynomials
To find:
Monomial of 2nd degree with leading coefficient 3
Solution:
Monomial is an algebraic expression with only one term.
Option A: 
It is not a monomial because it have 2 terms.
It is not true.
Option B:
It is not a monomial because it have 2 terms.
It is not true.
Option C: 
It have one term only. So, it is a monomial.
Degree means highest power. So degree = 2
Leading coefficient means the value before variable.
Leading coefficient = 3
It is true.
Option D: 
It have one term only. So, it is a monomial.
Degree means highest power. So degree = 3
It is not true.
Therefore
is a monomial of 2nd degree with a leading coefficient of 3.
What the heck are you saying? I think you need you fix the question