Unit 5 · Class 9 IB MYP · Formula Sheet

Circle Geometry Formulas — Class 9 IB MYP

Explore angle properties of circles, tangent-chord relationships, and inscribed angles.

Key Formulas

Angle at Centre

\text{Centre angle} = 2 \times \text{Inscribed angle}

Angle in Semicircle

90°

Cyclic Quadrilateral

\text{Opposite angles sum to } 180°

Tangent-Radius

\text{Perpendicular at point of contact}

Worked Examples

1Using: Supplementary Angles

If one angle is 65 degrees, find its supplement.

Step 1: Supplement = 180 - 65

Step 2: = 115 degrees.

Answer: 115 degrees

2Using: Vertically Opposite

Two lines intersect. If one angle is 40 degrees, find the vertically opposite angle.

Step 1: Vertically opposite angles are equal.

Step 2: The angle = 40 degrees.

Answer: 40 degrees

Practice Now

Apply these formulas with 60+ practice questions and AI-powered doubt clearing.

Practice Now

More Class 9 IB MYP Formulas

Real Number SystemQuadratic ExpressionsCoordinate GeometryLinear & Non-Linear FunctionsTrigonometry Introduction3D Geometry

Frequently Asked Questions

How many formulas are in Class 9 IB MYP Circle Geometry?+
There are 4 formulas in the Circle Geometry chapter for Class 9 IB MYP. Each formula is essential for solving problems in this topic.
How to remember Circle Geometry formulas easily?+
Practice regularly with worked examples, group related formulas together, and use SparkEd's interactive practice mode to reinforce your memory through problem-solving.
Are these Circle Geometry formulas enough for exams?+
Yes, these formulas cover the complete IB MYP Class 9 syllabus for Circle Geometry. Practice applying them to different types of questions for full exam readiness.

Master Circle Geometry on SparkEd

Go beyond formulas. Practice at three difficulty levels with instant feedback, step-by-step solutions, and an AI coach.

Start Practising Free

SparkEd Maths provides free formula sheets for Class 1-10 across 7 education boards. All formulas are aligned to the 2025-26 syllabus.