Question

ln triangle PQR, angle P-Q=20 and angle Q-R=50, find the value of angle R​

Answer 1

Answer:

               R = 20

Step-by-step explanation:

The sum of measures of angles in triangle is always 180°:

P + Q + R = 180

Q - R = 50    ⇒   Q = 50 + R

P - Q = 20    ⇒   P = 20 + Q = 20 + 50 + R = 70 + R

so:

  P  +  Q  +  R  =  180

70 + R + 50 + R + R = 180

120 + 3R = 180

    3R = 180 - 120

    3R = 60

     R = 60:3

      R = 20