Topic explanation

Standard explanation

Each is perp to the diameter. Two lines perp to the same line are parallel, so those tangents are parallel.

Key points

• parallel pair
• touches at one point
• radius perp tangent
• keep the ideas separate
• Tangents At Ends Of A Diameter: Each is perp to the diameter. Two lines perp to the same line are parallel, so those tangents are pa
• WHAT — TANGENTS AT ENDS OF A DIAMETER: Each is perp to the diameter. Two lines perp to the same line are parallel, so those tangents are pa
• HOW — Use the idea: Identify what is given, select this topic's rule or evidence, apply it one step at a time, and check
• CORE UNDERSTANDING: Each is perp to the diameter. Two lines perp to the same line are parallel, so those tangents are pa

Labelled diagram