Kat is painting the edge of a triangular stage prop with reflective orange paint. the lengths of the edges of the triangle are (3x – 4) feet, (x2 – 1) feet, and (2x2 – 15) feet. what is the perimeter of the triangle if x = 4?

16 feet
40 feet
76 feet
80 feet

Option B, 40 feet

Step-by-step explanation:

Kat is painting a triangular stage prop given with lengths of edges as (3x - 4) feet, (x² - 1) feet and (2x² - 15) feet

We have to calculate the perimeter of the triangular prop.

Since perimeter of the prop = sum of lengths of all sides of the triangle

= ( 3x - 4) + ( x² - 1 ) + ( 2x² - 15 )

= 3x - 4 + x² - 1 + 2x² - 15

= ( x² + 2x² ) + 3x - ( 4 + 1 + 15 )

= ( 3x² + 3x - 20 )

If x = 4 then

perimeter = 3 (4)² + 3 (4) - 20

                = 3 × 16 + 3 × 4 - 20

                = 48 + 12 - 20

                = 60 - 20

                = 40 feet

Option B, 40 feet is the answer.