You have an approximate idea of how far away something is.

I assume you keep track of your period," she said, "and at least have an approximate idea of when it should arrive.

It is difficult to give any approximate idea as to the year in which the work was composed.

We were enabled to form an approximate idea of the truth.

To get an approximate idea of infinity's dimensions, consider the vanity of architects.

An approximate idea of the Householder's method derives from the geometric series.

By checking the way light reflects from your eyes, the doctor gets an approximate idea of the lens prescription you need now.

"Even if a transcript is imperfect, it gives the user an approximate idea of what was said."

Thus we have an approximate idea of where to search.

Can you give us an approximate idea of the time of death.