Find the range of values for the third side of a triangle if two of its sides measure 42.7 mm and 38.03 mm:

A. [tex]4.4 \ \textless \ x \ \textless \ 80.73[/tex]
B. [tex]4.67 \ \textless \ x \ \textless \ 42.3[/tex]
C. [tex]4.04 \ \textless \ x \ \textless \ 80.1[/tex]
D. [tex]4.67 \ \textless \ x \ \textless \ 80.73[/tex]



Answer :

To determine the possible range of values for the third side of a triangle when the other two sides are known, we use the triangle inequality theorem. This theorem states that for any triangle with sides [tex]\(a\)[/tex], [tex]\(b\)[/tex], and [tex]\(c\)[/tex]:

1. [tex]\(a + b > c\)[/tex]
2. [tex]\(a + c > b\)[/tex]
3. [tex]\(b + c > a\)[/tex]

Given:
- Side [tex]\(a = 42.7\)[/tex] mm
- Side [tex]\(b = 38.03\)[/tex] mm

We need to find the range of possible values for the third side [tex]\(c\)[/tex].

### Step-by-Step Solution:

1. Calculate the lower bound:
[tex]\[ c > |a - b| \][/tex]
Substituting the values:
[tex]\[ c > |42.7 - 38.03| \][/tex]
[tex]\[ c > 4.67 \][/tex]
Therefore, the lower bound for [tex]\(c\)[/tex] is 4.67 mm.

2. Calculate the upper bound:
[tex]\[ c < a + b \][/tex]
Substituting the values:
[tex]\[ c < 42.7 + 38.03 \][/tex]
[tex]\[ c < 80.73 \][/tex]
Therefore, the upper bound for [tex]\(c\)[/tex] is 80.73 mm.

Combining these inequalities, we find that the third side [tex]\(c\)[/tex] must satisfy:
[tex]\[ 4.67 < c < 80.73 \][/tex]

Thus, the range of values for the third side of the triangle is:
[tex]\[ 4.67 < c < 80.73 \][/tex]

Among the given options, the correct one encapsulating this range is:
[tex]\[ \boxed{4.67 < x < 80.73} \][/tex]
This is the correct range for the possible values of the third side of the triangle.