Answer:
The value of the angle A is 71°
Step-by-step explanation:
First it is necessary to know that the sum of all the internal angles of the quadrilateral is 360°. then we can formulate the following equation:
Angle A + Angle B + Angle C + Angle D = 360°
Replacing every angle by the values given in the figure, we obtain:
(x+5) + (2x-1) + (x+8) + (84) = 360
Eliminating the parenthesis and Isolating the x on the equation:
x + 5 + 2x - 1 + x + 8 + 84 = 360
x + 2x + x + 5 - 1 + 8 + 84 =360
4x + 96 = 360
4x = 360 - 96
4x = 264
x =264/4
x=66
Now the value x is known, so the value of the angle A is:
Angle A = (x+5)°
replacing X by 66, it gets:
Angle A = (66+5)° = 71°
Finally, the value of the angle A is 71°
