Loading...

About Geometry Basics — Class 6 IB

Identify and classify angles, lines, triangles, and quadrilaterals in the plane. This topic is part of the IB Class 6 mathematics syllabus (chapter: Unit 6). On this page you can practice 60 questions across three difficulty levels — 20 easy, 20 medium, and 20 hard — each with a visual step-by-step solution, plus a timed 35-question mastery test with a live leaderboard. Worked examples and sample questions from the topic are below.

Geometry Basics — solved examples for Class 6 IB

Example 1easy

What is the sum of angles in a triangle?
  1. A)90°
  2. B)180°
  3. C)270°
  4. D)360°

Step-by-step solution

  1. The angles of any triangle always add up to 180°.

Answer: 180°

Example 2medium

Two angles on a straight line are x°x° and 130°130°. Find xx.
  1. A)40
  2. B)50
  3. C)60
  4. D)70

Step-by-step solution

  1. Solve:
    x=180°−130°=50°x = 180° - 130° = 50°

Answer: 50

Example 3hard

An exterior angle of a triangle is 130°. If one of the non-adjacent interior angles is 55°, find the other non-adjacent interior angle.
  1. A)50°
  2. B)65°
  3. C)75°
  4. D)85°

Step-by-step solution

  1. Other angle:
    130°−55°=75°130° - 55° = 75°

Answer: 75°

Practice questions on Geometry Basics

  1. Q1.easy

    A triangle has angles of 60° and 70°. What is the third angle?
    1. A)40°
    2. B)50°
    3. C)60°
    4. D)70°
    Show answer

    Answer: 50°

    Hint: Angles sum to 180°. Subtract the known angles.

  2. Q2.easy

    How many sides does a hexagon have?
    1. A)5
    2. B)6
    3. C)7
    4. D)8
    Show answer

    Answer: 6

    Hint: 'Hex' means six.

  3. Q3.easy

    What type of angle is 90°?
    1. A)Acute
    2. B)Right
    3. C)Obtuse
    4. D)Reflex
    Show answer

    Answer: Right

    Hint: Think of the corner of a book or page.

  4. Q4.medium

    Find the sum of interior angles of a pentagon.
    1. A)360°
    2. B)450°
    3. C)540°
    4. D)720°
    Show answer

    Answer: 540°

    Hint: Formula: (n − 2) × 180° where n = 5.

  5. Q5.medium

    In an isosceles triangle, the two equal angles are each 65°. What is the third angle?
    1. A)40°
    2. B)45°
    3. C)50°
    4. D)55°
    Show answer

    Answer: 50°

    Hint: Sum of all angles = 180°.

  6. Q6.medium

    Vertically opposite angles are always:
    1. A)Complementary
    2. B)Supplementary
    3. C)Equal
    4. D)Right angles
    Show answer

    Answer: Equal

    Hint: When two lines cross, the angles across from each other are equal.

  7. Q7.hard

    A quadrilateral has angles of x°x°, 2x°2x°, 3x°3x°, and 4x°4x°. Find the value of xx.
    1. A)30
    2. B)36
    3. C)40
    4. D)45
    Show answer

    Answer: 36

    Hint: Sum of angles = 360°. So x + 2x + 3x + 4x = 360.

  8. Q8.hard

    Two complementary angles are in the ratio 2 : 3. Find the larger angle.
    1. A)36°
    2. B)45°
    3. C)54°
    4. D)60°
    Show answer

    Answer: 54°

    Hint: Complementary = 90°. Total parts = 5.

  9. Q9.hard

    The interior angles of a polygon sum to 1080°. How many sides does it have?
    1. A)6
    2. B)7
    3. C)8
    4. D)9
    Show answer

    Answer: 8

    Hint: Use (n−2) × 180° = 1080°.

These are 9 of the 60 questions available for Geometry Basics. Start practicing above to unlock visual solutions, AI coaching, and the topic leaderboard — completely free.