Angles and circles for SQA National 5 Maths
This page covers the following topics:
1. Angle at the centre of the circle
2. Angles subtended by a semicircle
3. Angles in the same segment
4. Angles in cyclic quadrilaterals
5. Tangents and radii
The angle subtended at the centre of a circle is twice the angle subtended at the circumference.
The angle at the circumference of a semicircle is 90°.
Angles in the same segment are equal.
The sum of opposite angles in a cyclic quadrilateral is 180°.
A tangent to a circle is always perpendicular to the radius of that circle.
The angle subtended at the centre of a circle is 112°. What is the angle at the circumference?
What is a cyclic quadrilateral?
A cyclic quadrilateral is a 2D shape with four sides drawn inside a circle with every corner of the shape touching the circumference of the circle.
What is the size of angle y?
Do semicircles obey the rule that the angle at the centre of a circle is twice the angle subtended at the circumference of the centre?
Find the value of x.
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