Question

1 a triangle has side lengths of 15 centimeters, 11 centimeters, and 3.5x centimeters.
perimeter
a)
b) the perimeter is 75 centimeters.

Explanation:

Step1: Set up perimeter equation

$15 + 11 + 3.5x = 75$

Step2: Sum known side lengths

$26 + 3.5x = 75$

Step3: Isolate the variable term

$3.5x = 75 - 26$
$3.5x = 49$

Step4: Solve for x

$x = \frac{49}{3.5}$
$x = 14$

Step5: Find unknown side length

$3.5x = 3.5 \times 14$
$3.5x = 49$

Answer:

a) $x = 14$
b) The length of the unknown side is 49 centimeters.