This isosceles triangle has two sides of equal length, [tex]\( a \)[/tex], that are longer than the length of the base, [tex]\( b \)[/tex]. The perimeter of the triangle is 15.7 centimeters. The equation [tex]\( 2a + b = 15.7 \)[/tex] models this information.

If one of the longer sides is 6.3 centimeters, which equation can be used to find the length of the base?

[tex]\[
\begin{array}{l}
A. \ 6.3 + b = 15.7 \\
B. \ 12.6 + b = 15.7 \\
C. \ 2a + 6.3 = 15.7 \\
D. \ 2a + 126 = 15.7
\end{array}
\][/tex]



Answer :

Certainly! Let's go through the steps to determine which equation can be used to find the length of the base [tex]\( b \)[/tex] of the isosceles triangle.

We are given the following information:
1. The perimeter of the isosceles triangle is 15.7 centimeters.
2. The triangle has two sides of equal length, denoted by [tex]\( a \)[/tex], and a base of length [tex]\( b \)[/tex].
3. The equation modeling this information is [tex]\( 2a + b = 15.7 \)[/tex].
4. One of the longer sides [tex]\( a \)[/tex] is 6.3 centimeters.

Now, let's substitute the given value of [tex]\( a \)[/tex] into the equation to solve for [tex]\( b \)[/tex].

Starting from the perimeter equation:
[tex]\[ 2a + b = 15.7 \][/tex]

Substitute [tex]\( a = 6.3 \)[/tex] into the equation:
[tex]\[ 2 \cdot 6.3 + b = 15.7 \][/tex]

Simplify the expression:
[tex]\[ 12.6 + b = 15.7 \][/tex]

Therefore, the equation that can be used to find the length of the base [tex]\( b \)[/tex] is:
[tex]\[ 12.6 + b = 15.7 \][/tex]

So, the correct equation is [tex]\( 12.6 + b = 15.7 \)[/tex].

Among the given options, the correct answer is:
[tex]\[ 12.6 + b = 15.7 \][/tex]