Question

find the perimeter of the triangle. (21 - x) in. (2x - 3) in. (x + 5) in. the perimeter is inches.

Explanation:

Step1: Use the property of isosceles triangle

Since the two angles are marked as equal, the triangle is isosceles. So \(2x - 3=x + 5\).
Solve for \(x\):
\(2x-x=5 + 3\)
\(x = 8\)

Step2: Find the lengths of the sides

Substitute \(x = 8\) into each side length:

• First side: \(21-x=21 - 8=13\)
• Second side: \(2x-3=2\times8-3=13\)
• Third side: \(x + 5=8 + 5=13\)

Step3: Calculate the perimeter

Perimeter \(P=13+13+13=39\)

Answer:

\(39\)