The value of the variable x can be determined using the circle theorem to
determine the angle formed by x.
The correct responses are;
Reasons:
(1) From circle theorem, we have;
Therefore;
Angle subtended by [tex]\displaystyle \widehat {AB}[/tex] at center = Angle subtended by [tex]\widehat {BC}[/tex] at the center;
Therefore;
Angle subtended by [tex]\displaystyle \widehat {AB}[/tex] at the circumference = Angle subtended by [tex]\mathbf{\widehat {BC}}[/tex] at the circumference
Which gives;
(2) [tex]\displaystyle \widehat {AB} = \mathbf{\widehat {CD}}[/tex] given
Angle subtended by arc [tex]\widehat {CD}[/tex] at the center = x
Equal arcs subtend equal angles at the center of a circle.
Therefore;
Angle subtended by arc [tex]\mathbf{\widehat {AB}}[/tex] at the center = x
Angle at center = 2 × angle at circumference
Therefore;
x = 2 × 50° = 100°
x = 100°
(3) [tex]\displaystyle \widehat {AC} = \mathbf{ 3 \times \widehat {AB}}[/tex] given
By definition, we have;
Angle subtended by [tex]\widehat {AC}[/tex] at the center = 3 × Angle subtended by [tex]\widehat {AB}[/tex] at the center
According to circle theorem, we have;
Angle at the center = 2 × Angle at the circumference
Let y represent the angle subtended at the circumference by [tex]\widehat {AB}[/tex], we have;
y = 20°
[tex]\widehat {AB}[/tex] = 2·y
[tex]\widehat {AC}[/tex] = 3 × [tex]\widehat {AB}[/tex] = 3 × 2·y = 6·y
Therefore;
[tex]\widehat {AC}[/tex] = 6 × 20° = 120°
[tex]\widehat {AC}[/tex] = 120°
[tex]\widehat {AC}[/tex] = 2·x
Therefore;
2·x = 120°
[tex]\displaystyle x = \frac{120^{\circ}}{2} = \mathbf{ 60^{\circ}}[/tex]
x = 60°
Learn more circle theorems here:
https://brainly.com/question/16879446
