Primary 5 Mathematics Geometry Quiz

What is the sum of angles in a triangle?

• A) 90°
• B) 180°
• C) 270°
• D) 360°

In the triangle below, angle A = 65° and angle B = 40°. What is angle C?

• A) 65°
• B) 70°
• C) 75°
• D) 80°

Which of these shapes has exactly 2 lines of symmetry?

• A) Square
• B) Rectangle
• C) Equilateral triangle
• D) Regular hexagon

What type of angle is 95°?

• A) Acute
• B) Right
• C) Obtuse
• D) Reflex

How many faces does a cube have?

• A) 4
• B) 6
• C) 8
• D) 12

Find the missing angles: a) In triangle ABC, angle A = 55°, angle B = 75°. Find angle C. b) Angles on a straight line: 125° and x°. Find x.

Draw and name: a) An acute angle b) An obtuse angle c) A reflex angle

A regular pentagon has 5 equal sides and 5 equal angles. What is the size of each interior angle?

Look at the coordinate grid. What are the coordinates of: a) Point A at (3, 5) b) The point that is 2 units right and 3 units up from the origin

Draw the lines of symmetry for: a) An equilateral triangle b) A regular hexagon

Clock Problem At 3:00, what is the angle between the hour hand and the minute hand on a clock face?

Garden Design Problem Mr. Lim wants to design a triangular garden. Two angles of the triangle measure 45° and 55°. What is the third angle? What type of triangle is this?

Tessellation Problem Sarah is creating a tessellation pattern using regular hexagons. If she places 3 hexagons around a single vertex point, what is the angle left unfilled? (Each interior angle of a regular hexagon is 120°)

3D Shape Problem A gift box is in the shape of a cuboid with dimensions 20 cm × 15 cm × 10 cm. a) How many edges does this box have? b) How many vertices does this box have? c) How many faces does this box have?

B) 180°

• The sum of angles in any triangle is always 180°

C) 75°

• Angle C = 180° - 65° - 40° = 75°

B) Rectangle

• Rectangle has 2 lines of symmetry (horizontal and vertical through center)
• Square has 4, equilateral triangle has 3, regular hexagon has 6

C) Obtuse

• 95° is between 90° and 180°, so it's obtuse

B) 6

• A cube has 6 faces (top, bottom, front, back, left, right)

Missing angles: a) Angle C = 50° Working: 180° - 55° - 75° = 50°

b) x = 55° Working: 180° - 125° = 55°

Angle drawings: a) Acute angle: Any angle less than 90° (e.g., 45°, 60°) b) Obtuse angle: Any angle between 90° and 180° (e.g., 120°, 150°) c) Reflex angle: Any angle between 180° and 360° (e.g., 200°, 270°)

Each interior angle = 108° Working:

• Sum of interior angles = (5-2) × 180° = 540°
• Each angle = 540° ÷ 5 = 108°

Coordinates: a) Point A: (3, 5) Given in question

b) (2, 3) 2 units right and 3 units up from origin (0,0)

Lines of symmetry: a) Equilateral triangle: 3 lines of symmetry (from each vertex to opposite side midpoint) b) Regular hexagon: 6 lines of symmetry (3 through opposite vertices, 3 through opposite side midpoints)

Clock angle = 90° Working:

• At 3:00, minute hand points to 12, hour hand points to 3
• Each hour mark represents 30° (360° ÷ 12)
• Angle = 3 × 30° = 90°

Garden triangle:

• Third angle = 80°
• Scalene triangle (all angles different) Working:
• Third angle = 180° - 45° - 55° = 80°
• Since all angles are different, it's a scalene triangle

Unfilled angle = 0° Working:

• 3 hexagons at vertex: 3 × 120° = 360°
• Angle left unfilled = 360° - 360° = 0°
• The hexagons fit perfectly around the vertex

3D Shape properties: a) Edges = 12 b) Vertices = 8 c) Faces = 6

Working:

• A cuboid has:
  • 12 edges (4 on top, 4 on bottom, 4 vertical)
  • 8 vertices (corners)
  • 6 faces (top, bottom, front, back, left, right)