Inscribed Angles
Links and useful resources
- gr10's Geometry >>>START HERE<<<
- AoPS Online Textbook
- AoPS Alcumus
- Big Ideas Geometry textbook
- GeoGebra Online Geometry Constuction Tool
- Two-column math templates
- Proofs unit slides from mathgiraffe.com
- Proofs unit printables for two-column proofs
Concept summary and connections
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Inscribed angle in circle
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Inscribed angle in semicircle is right
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The measure of any angle inscribed in a circle (meaning that the angle's vertex and both rays intersect the circle) is always equal to half of the intersected arc.
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The measure of any angle inscribed in a semicircle so that the rays connect to the end points of the arc is always 90
Lesson and worked examples
- Useful tools for solving inscribed angle problems:
- Any triangle you make inside a circle where the center of the circle is a vertex will be isosceles (because two sides are equal to the radius)
- Any angle inscribed in a circle will have a measure equal to half the measure of the arc it intercepts
- All inscribed angles that intersect a semicirclular arc are right angles
Media resources
- Youtube search for "Inscribed angle in circle"
- Youtube search for "Inscribed angle in semicircle is right"