Answer :

Explanation:

In triangle DPQR, since PQ = QR = PR, it is an equilateral triangle, which implies that all angles are equal. If the measure of angle R (m R) is given by the expression (5x + 31)° and each angle in an equilateral triangle is 60°, we can set up the equation 5x + 31 = 60 to find the value of x.

To solve for x, follow these steps:

  1. Subtract 31 from both sides of the equation: 5x + 31 - 31 = 60 - 31.
  2. Simplify the equation: 5x = 29.
  3. Divide both sides by 5 to isolate x: x = 29/5.
  4. Therefore, x = 5.8.