Question

find the value of a.
perimeter = 120 centimeters
a = centimeters

Explanation:

Step1: Recall the perimeter formula

Perimeter of a triangle \(P = s_1 + s_2 + s_3\). Here \(P = 120\), \(s_1=40\), \(s_2 = 40\), \(s_3=a\).

Step2: Substitute values into formula

\(120=40 + 40+a\).

Step3: Simplify the equation

First, \(40 + 40=80\). So the equation becomes \(120=80 + a\).

Step4: Solve for \(a\)

Subtract \(80\) from both sides: \(a=120 - 80\).

Answer:

\(40\)