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 perimeter of triangle

Perimeter of a triangle is sum of all sides. For isosceles triangle, two sides (x) are equal, and third side is y. So perimeter \( P = 2x + y \).

Step2: Substitute known values

Given \( P = 7.5 \) m and \( y = 2.1 \) m. Substitute into formula: \( 2x + 2.1 = 7.5 \) (or \( 2.1 + 2x = 7.5 \)).

Answer:

\( 2.1 + 2x = 7.5 \) (the last option, e.g., if options are labeled as A, B, C, D with D being \( 2.1 + 2x = 7.5 \), then D. \( 2.1 + 2x = 7.5 \))