Respuesta :

Answer:

26.8°

Step-by-step explanation:

4x - 20 + 6x - 7 = 90

10x -27 =90

10x = 90+27

10x= 117

x = 11.7

so, the angle R = 4x-20 =4(11.7)-20

= 46.8-20 = 26.8°