Question

3. PQR is an isosceles triangle with PQ = PR, and angle QPR = x".

Answer 1

Answer:

a). Perimeter = (5r + 9) cm

b). r = 8

Step-by-step explanation:

Property of isosceles triangle:

- Two sides of an isosceles triangle are equal.

- Opposite sides of the equal angles are equal in measure.

  From the figure attached,

  PQ = QR = (2r + 3)

a). Since perimeter of a polygon = sum of all sides of the polygon

                                                 = PQ + QR + PR

                                                 = (2r + 3) + (2r + 3) + (r + 3)

                                                 = 5r + 9

    Perimeter of the given triangle = (5r + 9) cm

b). Perimeter of the given triangle = 49 cm

    (5r + 9) = 49

     5r = 40

      r = 8