Unit 7 · Class 9 IB MYP · Formula Sheet

3D Geometry Formulas — Class 9 IB MYP

Calculate surface area and volume of pyramids, cones, and spheres; solve composite solid problems.

Key Formulas

Volume of Pyramid

V = \dfrac{1}{3} \times \text{Base Area} \times h

Volume of Cone

V = \dfrac{1}{3}\pi r^2 h

Volume of Sphere

V = \dfrac{4}{3}\pi r^3

SA of Sphere

\text{SA} = 4\pi r^2

CSA of Cone

\pi r l

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

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More Class 9 IB MYP Formulas

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Frequently Asked Questions

How many formulas are in Class 9 IB MYP 3D Geometry?+
There are 5 formulas in the 3D Geometry chapter for Class 9 IB MYP. Each formula is essential for solving problems in this topic.
How to remember 3D 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 3D Geometry formulas enough for exams?+
Yes, these formulas cover the complete IB MYP Class 9 syllabus for 3D Geometry. Practice applying them to different types of questions for full exam readiness.

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