If the cone is cut along its axis from the middle , the new shape we obtain after opening the paper is :

Options

A. a. isosceles triangle
B. b. equilateral triangle
C. c. right angle triangle
D. d. none of these

Answer

To solve the question, "If the cone is cut along its axis from the middle, the new shape we obtain after opening the paper is:", we can follow these steps:

### Step-by-Step Solution:

1. **Understanding the Cone**:
- A cone is a three-dimensional geometric shape that tapers smoothly from a flat base (circular) to a point called the apex.

2. **Cutting the Cone**:
- When we cut the cone along its axis from the middle, we are essentially slicing it vertically down the center. This means we will divide the cone into two equal halves.

3. **Opening the Cone**:
- After cutting the cone, if we were to "open" the paper (which represents the surface of the cone), we would unfold it.

4. **Shape of the Unfolded Cone**:
- The surface area of a cone can be represented as a sector of a circle when it is unfolded.
- The base of the cone remains circular, and the lateral surface area forms a sector of a circle.

5. **Identifying the Resulting Shape**:
- When we cut the cone and unfold it, we will have two identical shapes that resemble a triangle (specifically an isosceles triangle) with a circular base.
- The apex of the triangle corresponds to the apex of the cone, and the base corresponds to the circumference of the cone's base.

6. **Conclusion**:
- Thus, the new shape we obtain after opening the paper is two isosceles triangles (one for each half of the cone).

### Final Answer:
The new shape obtained after cutting the cone along its axis and opening the paper is two isosceles triangles.