The angle at the circumference is half that at the center
The angle at the circumference is double that at the center
Angles in isosceles triangles are equal
Question 2
Question
Angle x = [blank_start]100[blank_end] because angles at the center of a circle [blank_start]are double that at the circumference[blank_end].
Also y = [blank_start]80[blank_end] [blank_start]for the same reason[blank_end].
O is the centre of a circle
Angle STU = [blank_start]90[blank_end],
Angle z = [blank_start]59[blank_end],
because [blank_start]the angle in a semicircle is 90[blank_end]