Geometry
Triangles
A triangle is a polygon with three sides. The angles sum to 180°.
Key Formulas
Area
Base times height divided by 2.
Pythagorean theorem
For right triangles only.
Key Concepts
Types of trianglesCongruenceSimilarityPythagorean theorem
Worked Examples
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Solution:
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Angles
An angle is formed by two rays sharing a common endpoint. Angles are measured in degrees or radians.
Circles
A circle is the set of points equidistant from a center point. It is defined by its radius or diameter.
Area
Area measures the amount of space inside a two-dimensional shape.
Volume
Volume measures the amount of space inside a three-dimensional object.