ICSE-VIII-Mathematics

16: Understanding Shapes (Including Polygons) Class 8 Maths

with Solutions -
  • #5
    (i) If all the angles of a hexagon are equal; find the measure of each angle. (ii) If all the angles of a 14-sided figure are equal; find the measure of each angle.
    Ans : (i) No. of sides of hexagon, n = 6
    Let each angle be = x°
    Sum of angles = 6x°
    (n - 2)× 180° = Sum of angles
    ⇒ (6 - 2)× 180° = 6x°
    ⇒ 4× 180 = 6x
    ⇒ x = (4 × 180)/6
    ⇒ x = 120˚
    ∴ Each angle of hexagon = 120˚ (ii) No. of sides of polygon, n = 14
    Let each angle = xËš
    ∴ Sum of angles = 14x˚
    ∴ (n - 2) × 180˚ = Sum of angles of polygon
    ∴ (14 - 2) × 180˚ = 14x
    12 × 180˚ = 14x
    ⇒ x = (12 × 180)/14
    ⇒ x = 1080/7
    ⇒ x = (154 2/7)˚
  • #5-i
    If all the angles of a hexagon are equal; find the measure of each angle.
    Ans : No. of sides of hexagon, n = 6
    Let each angle be = x°
    Sum of angles = 6x°
    (n - 2)× 180° = Sum of angles
    ⇒ (6 - 2)× 180° = 6x°
    ⇒ 4× 180 = 6x
    ⇒ x = (4 × 180)/6
    ⇒ x = 120˚
    ∴ Each angle of hexagon = 120˚
  • #5-ii
    If all the angles of a 14-sided figure are equal; find the measure of each angle.
    Ans : No. of sides of polygon, n = 14
    Let each angle = xËš
    ∴ Sum of angles = 14x˚
    ∴ (n - 2) × 180˚ = Sum of angles of polygon
    ∴ (14 - 2) × 180˚ = 14x
    12 × 180˚ = 14x
    ⇒ x = (12 × 180)/14
    ⇒ x = 1080/7
    ⇒ x = (154 2/7)˚