Two parallelograms are on equal bases and between the same parallels.
The ratio of their areas is

Options

A. `1 : 2`
B. `1 : 1`
C. `2 : 1`
D. `3 : 1`

Explanation

To solve the problem, we need to understand the properties of parallelograms that share equal bases and are situated between the same parallels.

### Step-by-Step Solution:

1. **Understanding the Properties of Parallelograms**:
- A parallelogram is defined by its base and height. The area of a parallelogram can be calculated using the formula:
\[ \text{Area} = \text{Base} \times \text{Height} \]

2. **Identifying the Given Information**:
- We have two parallelograms that are on equal bases. This means that the length of the base of both parallelograms is the same.
- Both parallelograms are situated between the same parallels, which indicates that they have the same height.

3. **Calculating the Areas**:
- Let the length of the base be \( b \) and the height be \( h \).
- The area of the first parallelogram (Area 1) can be expressed as:
\[ \text{Area 1} = b \times h \]
- The area of the second parallelogram (Area 2) is also:
\[ \text{Area 2} = b \times h \]

4. **Finding the Ratio of Areas**:
- Since both areas are equal, we can set up the ratio:
\[ \text{Ratio of Areas} = \frac{\text{Area 1}}{\text{Area 2}} = \frac{b \times h}{b \times h} = 1 \]
- Therefore, the ratio of the areas of the two parallelograms is:
\[ 1 : 1 \]

5. **Conclusion**:
- The ratio of the areas of the two parallelograms is \( 1 : 1 \).