Question

a circular picture whose diameter is 4 decimeter is framed in a rectangle board with dimension of 6 decimeter by 4 decimeter what is the area of the board that can be seen​

Answer 1

Answer is $\bf \dfrac{80}{7}$ dm².

In order to calculate the area of the board that can be seen, we need to calculate the area of the the rectangular board and the circular frame. The difference of both's area is the required answer.

Refer to the attachment for step by step solution. :)