Answer:
16
Step-by-step explanation:
We can see that Ar is the perpendicular bisector of chord BD. Since A is the center of the circle, AR is the radius of the circle, which is 10 (6+4)
Next, we can see that when we connect point A to point D, it is also a radius. Thus, AD is also equal to 10 as the radius of the circle remains the same.
Using Pythagoras theorem, a^2 + b^2 = c^2, we can make a right angled triangle of ACD.
AC = 6 = a
CD = ? = b
AD = 10 = c
10^2 = 6^2 + b^2
b^2 = 10^2 - 6^2 = 64
b = CD = 8
Now, since Ar is the perpendicular bisector of chord BD, BD = CD x 2
BD = 8 x 2 = <u>16</u>
<ABC would equal 106
seeing in triangle ABD angle A equals 67 you would multiply that by 2 and then subtract it from 180 to get 46, and then triangle DBC all the angles would equal 60. so then add 46 to 60 to get 106 the measure of <ABC
the angle measures in the regular polygon is B)140
