Respuesta :

Blitztiger
For any inscribed quadrilateral, the sum of each pair of opposite angles must add up to 180. In this case, B + A = 180, and similarly, E + R = 180. Therefore,
74 + R = 180
R = 106 degrees

(Similarly, if we had to solve for B, B + 92 = 180, and B = 88 degrees.)
Matheng
The opposite angles in any inscribed quadrilateral are supplementary.
∵ ∠E + ∠R = 180°
∴ ∠R = 180 - ∠E = 180° - 74° = 106°