Question

the isosceles triangle has a perimeter of 7.5 m. which equation can be used to find the value of x if the shortest side, y, measures 2.1 m? 2x - 2.1 = 7.5 4.2 + y = 7.5 y - 4.2 = 7.5 2.1 + 2x = 7.5

Explanation:

Step1: Recall the perimeter formula of a triangle

The perimeter \(P\) of a triangle is \(P=a + b + c\), where \(a\), \(b\), and \(c\) are the side - lengths of the triangle.

Step2: Analyze the isosceles triangle

For an isosceles triangle with two equal sides \(x\) and the third side \(y\), the perimeter formula is \(P=x + x + y\).

Step3: Substitute the given values

Given \(P = 7.5\) m and \(y=2.1\) m. Substituting into the formula \(P = 2x + y\), we get \(7.5=2x + 2.1\)

Answer:

\(2.1 + 2x=7.5\) (the fourth option)