Question

Find m/_A

66°
71°
21°
26°

Answer 1

The sum of the measures of the internal angles in the quadrilateral is 360°.

Therefore:

`x+5+2x-1+84+x+8=360\\\\4x+96=360\ \ \ |-06\\\\4x=264\ \ \ |:4\\\\x=66`
Answer: x = 66°.

Answer 2

The value of the angle A is 71°

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°