The measure of angle A is 65°
Step-by-step explanation:
Given that ABCD is a quadrilateral inscribed in a circle.
The measure of angle A is
![\angle A=(2x+1)^(\circ)](https://img.qammunity.org/2021/formulas/mathematics/high-school/4z21n20q9wa7tb9dkt61tqghdnfl1s3tsg.png)
The measure of angle B is
![\angle B=148^(\circ)](https://img.qammunity.org/2021/formulas/mathematics/high-school/awodd6ljcxzt1yzsgjv1atz5cqni38pwwn.png)
The measure of angle D is
![\angle D=x^(\circ)](https://img.qammunity.org/2021/formulas/mathematics/high-school/gsuyiaosii47v2ob5wzv6yfcp2ez3mgccg.png)
We need to determine the measure of angle A.
Since, we know that the angles B and D are opposite angles and the opposite angles of a quadrilateral add up to 180°
Thus, we have,
![\angle B+\angle D=180^(\circ)](https://img.qammunity.org/2021/formulas/mathematics/high-school/ftxly06gxty5y85fm7t1ij58xwq6p86sku.png)
Substituting the values, we have,
![148^(\circ)+x=180^(\circ)](https://img.qammunity.org/2021/formulas/mathematics/high-school/xd0vnef4p2mftnia1az5lfesn5oncr7w4e.png)
![x=32^(\circ)](https://img.qammunity.org/2021/formulas/mathematics/high-school/vlu4zxb1929ejd00nzobxx1el7oartz2il.png)
Thus, the value of x is 32°
Substituting the value of x in the measure of angle A, we get,
![\angle A=(2x+1)^(\circ)](https://img.qammunity.org/2021/formulas/mathematics/high-school/4z21n20q9wa7tb9dkt61tqghdnfl1s3tsg.png)
![\angle A=(2(32)+1)^(\circ)](https://img.qammunity.org/2021/formulas/mathematics/high-school/3sfp6kobgxo55ssobswza0xabm8g3hdjfc.png)
![\angle A=(64+1)^(\circ)](https://img.qammunity.org/2021/formulas/mathematics/high-school/b0dkxf1h4349a0hxbd0jaq22q314uuxbmg.png)
![\angle A=65^(\circ)](https://img.qammunity.org/2021/formulas/mathematics/high-school/cpu8qs9uwtqwbu8u7ex1ulhyxa5m5yf45c.png)
Thus, the measure of angle A is 65°