Circle TheoremsSix results that solve almost every circle question.10th GradeAngles and lines in circles follow fixed relationshipsdetermined by the centre and the arcs they subtend.central angle = 2 × inscribed angleAngle in a semicircle90°Any triangle on the diameter is right-angled.Central vs inscribedcentral is doubleBoth standing on the same arc.Same arcinscribed angles equalWherever the vertex sits on the major arc.Tangent and radiusperpendicularA tangent meets the radius at 90°.Opposite angles in a cyclic quadrilateral add to 180°. That one getsforgotten most often.Circle Theoremslearnposters.com
Circle Theorems — printable math wall chart from LearnPosters. Free vector PDF, US Letter and A4.

What’s on the Circle Theorems poster

The rule, 4 worked examples.

Opposite angles in a cyclic quadrilateral add to 180°. That one gets forgotten most often.

Questions about the Circle Theorems poster

What’s on the Circle Theorems poster?
The rule, 4 worked examples. Angles and lines in circles follow fixed relationships determined by the centre and t…; central angle = 2 × inscribed angle; Angle in a semicircle = 90°; Central vs inscribed = central is double; Same arc = inscribed angles equal; Tangent and radius = perpendicular. Opposite angles in a cyclic quadrilateral add to 180°. That one gets forgotten most often.
Who is the Circle Theorems poster for?
Circle Theorems is filed under 10th Grade (ages 15–16), so it matches what that year asks a child to remember. It is equally useful to an older student revisiting math, and to the parent or teacher answering the question at the kitchen table.
When should you use the Circle Theorems poster?
Look for the diameter and for the centre. Both trigger specific theorems. A wall chart earns its place by being glanceable from where the work is happening, so Circle Theorems belongs on the wall where that math work actually happens, within glancing distance, rather than filed away.
What other posters go with Circle Theorems?
Coordinate Proofs, Angles in Polygons and Sequences and Series sit alongside Circle Theorems in the 10th Grade set. Printed together they make a wall rather than a single sheet, which is how a reference set actually gets used.Coordinate ProofsAngles in PolygonsSequences and Series
Is the Circle Theorems poster free to download and print?
Yes. Circle Theorems downloads as a free PDF with no account, no email and no watermark, like everything else in the 10th Grade set. Print as many copies as you like for a home, a classroom, a library or a tutoring group; reselling the file is the only thing the licence rules out.Read the licence
What size does the Circle Theorems poster print at?
Circle Theorems is a vector PDF laid out for US Letter, and prints on A4 with Fit to page — the same file, no separate download. Because every mark on it is drawn rather than photographed, it stays sharp enlarged to A3, A2 or A1 at a copy shop. Colour carries emphasis only, so a greyscale print of Circle Theorems loses nothing.Printing guide

Related posters

Charts that sit alongside Circle Theorems on the same wall.

Browse every 10th Grade poster, or start from the full catalogue.