Question

I need help with these questions (see image). Please show workings.
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Answer 1

y=58×2=116 central angle of the cyclic quadrilateral is double if inscribed angle

z=90/2=45

inscribed angle is half of central angle of the cyclic quadrilateral

Answer 2

• Inscribed angle is half of the intercepted arc.
• Central angle is the same size as the intercepted arc.

As per above two statements we have:

• y = 2*58° = 116°

and

• z = 90°/2 = 45°