The perimeter of a triangle is 25 feet. What is the length of the unknown side?

Perimeter of triangle=sum of all sides x= unknown sides

Step-by-step explanation:

25ft= x+ 5.2ft + 8ft

25ft= x + 13.2ft

subtract 13.2 from both sides

11.8 feet = x

unknown side is 11.8 feet

option a is correct.

step-by-step explanation:

scale factor: it is used to find proportional measurements.

proportions means having the same ratio.

scale factor is the ratio of the model measurement to the actual measurement in a simplest form.

or we can say that the ratio of any two corresponding lengths in two similar geometric figures

if the scale factor is more than 1, then it is an enlargement,

if the scale factor less than 1, then it is a reduction.

given the two geometric figure:

by definition of proportions, we have