Quadrilateral ABCD ​ is inscribed in this circle.



What is the measure of angle C?

Enter your answer in the box.


°




A quadrilateral inscribed in a circle. The vertices of the quadrilateral lie on the edge of the circle and are labeled as A, B, C, D. The interior angle A is labeled as left parenthesis 2 x plus 3 right parenthesis degrees. The angle B is labeled as left parenthesis 2 x minus 4 right parenthesis degrees. The angle D is labeled as left parenthesis 3 x plus 9 right parenthesis degrees.

Respuesta :

The measure of angle C is 107°

Explanation:

Given that ABCD is a quadrilateral.

The vertices A, B, C, D lie on the edge of the circle.

The measure of angle A is [tex]\angle A=(2x+3)^{\circ[/tex]

The measure of angle B is [tex]\angle B=(2x-4)^{\circ}[/tex]

The measure of angle D is [tex]\angle D=(3x+9)^{\circ}[/tex]

We need to determine the measure of angle C

Since, we know that the opposite angles B and D are supplementary.

Thus, we have,

[tex]\angle B+\angle D=180^{\circ}[/tex]

Substituting the values, we get,

[tex]2x-4+3x+9=180[/tex]

             [tex]5x+5=180[/tex]

                    [tex]5x=175[/tex]

                     [tex]x=35[/tex]

Thus, the value of x is 35

Substituting the value of x in the measures of angles A, B and D, we get,

[tex]\angle A=(2(35)+3)^{\circ[/tex]

[tex]\angle A=(70+3)^{\circ[/tex]

[tex]\angle A=73^{\circ[/tex]

Similarly, [tex]\angle B=(2x-4)^{\circ}[/tex]

[tex]\angle B=(2(35)-4)^{\circ}[/tex]

[tex]\angle B=(70-4)^{\circ}[/tex]

[tex]\angle B=66^{\circ}[/tex]

For angle D, we have,

[tex]\angle D=(3(35)+9)^{\circ}[/tex]

[tex]\angle D=(105+9)^{\circ}[/tex]

[tex]\angle D=114^{\circ}[/tex]

Now, we shall find the measure of angle C

Since, we know that all the angles in a quadrilateral add up to 360°

Thus, we have,

[tex]\angle A+\angle B+\angle C+\angle D=360^{\circ[/tex]

Substituting the values of A, B and D, we get,

[tex]73^{\circ}+66^{\circ}+\angle C+114^{\circ}=360^{\circ}[/tex]

                  [tex]253^{\circ}+\angle C=360^{\circ}[/tex]

                             [tex]\angle C=107^{\circ}[/tex]

Thus, the measure of angle C is 107°

Answer:

measure of angle C is 107°

Step-by-step explanation:

Verified correct with test results.