Question

Quadrilateral ABCD ​ is inscribed in a circle.

Answer 1

Answer:

$m\angle A=\boxed{135}\,^\circ$

Step-by-step explanation:

Opposite angles of an inscribed quadrilateral are supplementary, so ...

  m∠A + m∠C = 180°

Substituting the given expressions, we have ...

  (3x +6)° + (x+2)° = 180°

  4x +8 = 180 . . . . . . collect terms, divide by °

  x +2 = 45 . . . . . . . . divide by 4

  3x +6 = 135 . . . . . . multiply by 3

This is the value of angle A in degrees, so ...

  m∠A = 135°