Question

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

Answer 1

Perimeter of triangle =40 feet

Explanation:

Given:

Lengths of edges of triangle:

`(3x-4)` feet

`(x^2-1)` feet

`(2x^2-15)` feet

Perimeter of the triangle= Sum of all sides =
`(3x-4)+(x^2-1)+(2x^2-15)` feet

On simplifying by adding like terms:

Perimeter of triangle =
`3x^2+3x-20` feet

Given
`x=4`

∴ Perimeter of triangle =
`3(4)^2+3(4)-20`
`=3(16)+12-20`

`=48+12-20` = 40 feet