Exploring Some Geometric Terms Exercise 4.1 Class 8 Maths – Chapter 4 NCERT Solutions
This page provides detailed NCERT Class 8 Maths Chapter 4 Exercise 4.1 solutions, prepared by the faculty at ALLEN to help students understand the concepts, follow the correct approach to each question, and practise the exercise effectively for their exams.Exercise 4.1 focuses on the Sierpinski Triangle, its step-by-step construction, geometric patterns, and changes in the number of triangles, holes, and area at different stages.
1.0Download Class 8 Maths Chapter 4 Ex 4.1 NCERT Solutions PDF
Download the free PDF of Class 8 Maths Chapter 4 Exercise 4.1 NCERT Solutions for convenient offline practice and reference.
2.0Detailed NCERT Solutions on Geometric Terms Exercise 4.1 Class 8 Maths (Ganita Prakash Term 2)
- Draw the initial few steps (at least till Step of the shape sequence that leads to the Sierpinski Triangle.
Sol. Step-0: Take cut out of an equilateral triangle Δ.
Step-1: Divide it into 4 equilateral triangles by joining the midpoints of each of the sides. Remove the central triangle.
Step-2: Divide each of the remaining 3 equilateral triangles into four equilateral triangles and remove the central triangle in each of them.
Step-3: Repeat the steps again and again to get Sierpinski's gasket.
2. Find the number of holes, and the triangles that remain at each step of the shape sequence that leads to the Sierpinski Triangle.Sol. Number of holes in
Step-0: 0 hole
Step-1: 1 hole
Step-2: 1+3=4 holes
Step-3: 1+3+9=13 holes
Step-4: 1+3+9+27=40 holes.
Step n: 31−1+32−1+33−1+……+3n−1 holes
=30+31+32+……+3n−1 holes
- Find the area of the region remaining at the nth step in each of the shape sequences that lead to the Sierpinski fractals. Take the area of the starting square/triangle to be 1 sq. unit.
Sol. (a) Let the side of the square of s Sierpinski's Carpet be 1 square unit. As one-ninth of the square is removed, and one-eighth remains in each step.
Step-0: Area of whole square
=(1)2=1
Step-1: Area of remaining region
=98(1)2=98
Step-2: Area of remaining region
=98×98=8164
Step-3: Area of remaining region
=98×8164=9383=729512
Area of remaining region after nth step
=(98)n sq. units
(b) let the area of the triangle of sierpinkski's Gasket be 1 aquare unit.
One fourth of the triangle is removed in each step, and three fourth remains.
Step-0: Area of the whole triangle =1 sq. unit
Step-1: Area of remaining region =43 sq. unit
Step-2: Area of remaining region =43×43 sq. unit =169 square unit Area of remaining region after nth step =(43)n sq. units
3.0Key Concepts of Chapter 4 Geometric Terms Exercise 4.1
- Fractals and their repeating geometric patterns
- Construction of the Sierpinski Triangle through successive stages
- Patterns in the number of triangles and holes at different stages
- Area patterns in the Sierpinski Triangle
- Construction and area pattern of the Sierpinski Carpet
- Construction and area pattern of the Sierpinski Gasket
- Identifying and generalising patterns that continue up to the nth step
4.0Benefits of NCERT Solutions Class 8 Maths Chapter 4 Exercise 4.1
- Helps understand the repeating patterns formed through the construction of the Sierpinski Triangle.
- Makes it easier to follow changes in the number of triangles and holes at different steps.
- Clarifies how the area of the remaining region changes as the construction progresses.
- Explains the area patterns associated with the Sierpinski Carpet and Sierpinski Gasket.
- Helps identify mathematical patterns and extend them to the nth step.
- Provides clear solutions for questions based on successive stages of fractal construction.
- Makes the pattern-based reasoning in Exercise 4.1 easier to follow and revise.