Question

In triangle pqr PQ = 3x QR = 4
x PR = 5 x and the perimeter of the triangle is 72 cm find the value of x

Answer 1

Answer:

x = 6

Step-by-step explanation:

perimeter = sum of all sides

72 = PQ + QR + PR

72 = 3x + 4x + 5x

72 = 12x

72÷ 12 = x

6 = x

x = 6.

Answer 2

Given,

In ΔPQR,

PQ =3x, QR = 4x, PR = 5x, and

Perimeter of ΔPQR = 72 cm.

To find,

Value of x.

Solution,

This problem can be simply solved following the process given below.

Here, the three sides of a ΔPQR, that is PQ, QR, and PR are given in terms of x. That is,

PQ = 3x

QR = 4x, and

PR = 5x

Also, the perimeter of the ΔPQR is given as equal to 72 cm.

Now, as we know that the perimeter of a triangle is defined as the sum of all three sides of the triangle. Therefore, here, for the given triangle,

Perimeter = PQ + QR + PR

Or, 72 = PQ + QR + PR

Substituting the given values for PQ, QR and PR in above equation and rearranging, we obtain,

3x + 4x + 5x = 72

⇒ 12x = 72

⇒ x = 6.

Therefore, the value of x will be 6.