Answer:
QR = 4x - 6
Step-by-step explanation:
A triangle is a polygon that has three sides and three angles. There are different types of triangles such as equilateral triangle, isosceles triangle, scalene triangle, right angled triangle.
The perimeter of a triangle is a measure of the length of the sides. It is the sum of all the length of the three sides of the triangle.
From the question:
Perimeter of triangle PQR = PQ + PR + QR
But PR = 3x - 1, PQ = x + 1, Perimeter of PQR = 8x - 6.
Therefore substituting gives:
8x - 6 = (x + 1) + (3x - 1) + QR
8x - 6 = (x + 3x + 1 - 1) + QR
8x - 6 = 4x + QR
QR = (8x - 6) - 4x
QR = 4x - 6
