Pablo folds a straw into a triangle with side lengths of 4x2−3 inches, 4x2−2 inches, and 4x2−1 inches. Which expression can be used to find the perimeter of the triangle, and what is the perimeter when x = 1.5?
12x2 −6; 21 inches
12x2; 27 inches
12x2 −6; 30 inches
12x2; 36 inches
To find the perimeter of a triangle, we need to add up the lengths of all three sides.
Given that the side lengths are 4x^2-3 inches, 4x^2-2 inches, and 4x^2-1 inches, the expression that can be used to find the perimeter is:
Perimeter = (4x^2-3) + (4x^2-2) + (4x^2-1)
When x = 1.5, we can substitute this value into the expression to find the perimeter:
Perimeter = (4(1.5)^2-3) + (4(1.5)^2-2) + (4(1.5)^2-1)
Perimeter = (4(2.25)-3) + (4(2.25)-2) + (4(2.25)-1)
Perimeter = (9-3) + (9-2) + (9-1)
Perimeter = 6 + 7 + 8
Perimeter = 21 inches
Therefore, the correct answer is:
12x^2 - 6; 21 inches