Answer:
[tex]Base = 57[/tex]
Step-by-step explanation:
Given
[tex]Length = 2x + 4[/tex]
[tex]Base = 3x[/tex]
[tex]Perimeter = 141[/tex]
Required
Determine the length of the base
The perimeter of an isosceles triangle is:
[tex]Perimeter = 2*Length + Base[/tex]
[tex]141 = 2 (2x + 4) + 3x[/tex]
[tex]141 = 4x + 8 + 3x[/tex]
Collect Like Terms
[tex]4x + 3x = 141 - 8[/tex]
[tex]7x = 133[/tex]
Divide both sides by 7
[tex]x = 19[/tex]
To get the base, we substitute 19 for x in [tex]Base = 3x[/tex]
[tex]Base = 3 * 19[/tex]
[tex]Base = 57[/tex]
