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Class 3 Maths Adventure

Points, Lines, Rays, Angles

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Hi! I'm Vidi. Let's learn Points, Lines, Rays, Angles together — read with me, then play the games to win a ⭐!

🔵Point, Line Segment, Ray, and Angle

Geometry starts with basic building blocks:

  • Point: An exact location in space (shown as a dot •)
  • Line segment: A straight path with two endpoints (A________B)
  • Ray: Starts at one endpoint and continues forever in one direction (→)
  • Angle: Formed by two rays sharing the same endpoint (vertex)
Point AABLine Segment ABCRay CDAngle at ETwo rays from same point = angleThe shared point = vertex
👀 See a worked example
What geometry term describes the tip of a pencil? A point. A point marks an exact location with no size.
Which goes on forever in one direction: a line segment or a ray? A ray. It starts at a point and extends forever in one direction.
The corner of a book models what geometry term? An angle (specifically a right angle).

🤖 Vidi's Key Points

  • Point = dot (no size). Line segment = 2 endpoints. Ray = 1 endpoint, goes forever.
  • Angle = 2 rays from same point (vertex).
  • Line segment is part of a line; ray is half a line.

🟢Classify Angles: Right, Acute, Obtuse

Angles are classified by their size (measured in degrees °):

  • Right angle: Exactly 90° — looks like a perfect corner (L shape)
  • Acute angle: Less than 90° — smaller than a right angle (sharp, narrow)
  • Obtuse angle: More than 90° — larger than a right angle (wide, blunt)

A small square symbol in the corner means it is a right angle.

Right (90°)Corner of paperAcute (<90°)Sharp, less than 90°Obtuse (>90°)Wide, more than 90°
👀 See a worked example
What angle is at the corner of a square? A right angle (90°). All four corners of a square are right angles.
A slightly open book makes a sharp angle. What type is it? Acute angle — less than 90°, narrow and sharp.
A wide-open door makes a large angle. What type is it? Obtuse angle — more than 90°, wide and open.

🤖 Vidi's Key Points

  • Right = exactly 90° (square corner). Acute = less than 90° (sharp). Obtuse = more than 90° (wide).
  • Compare to the corner of a piece of paper: that is 90°.
  • Acute is smaller than right; obtuse is bigger than right.

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