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

Explanation:

Step1: Substitute x = 4 into first side

Substitute \(x = 4\) into \(3x-4\).
\[3\times4 - 4=12 - 4=8\]

Step2: Substitute x = 4 into second side

Substitute \(x = 4\) into \(x^{2}-1\).
\[4^{2}-1=16 - 1 = 15\]

Step3: Substitute x = 4 into third side

Substitute \(x = 4\) into \(2x^{2}-15\).
\[2\times4^{2}-15=2\times16-15=32 - 15 = 17\]

Step4: Calculate perimeter

Add the three side - lengths together.
\[8 + 15+17=40\]

Answer:

40 feet