Respuesta :

devishri1977

Answer:

58°

Step-by-step explanation:

Angle sum property of triangle:

  The sum of all angles of a triangle is 180°.

 x + 69 + 55 + x + 78 = 180

  x + x + 69 + 55 + 78 = 180

Combine like terms,

                   2x + 202 = 180

Subtract 202 from both sides,

                              2x = 180 - 202

                              2x = -22

Divide both sides by 2,

                                 x = -22/2

                                 x = -11

∠A = x + 69

     = -11 + 69

 [tex]\sf \boxed{\angle A= 58^\circ}[/tex]

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