Answer:
I don't know about this thing
The answer:
First: sec(-pi) is sec(pi)
And sec(pi) is -1
Answer:
THE ANSWER WOULD BE TRUE MY FRIEND
When you estimate, you round each number, the add.
We round them to
700+620, which is 1320
So our non estimated answer is 1323
But our estimated answer is 1320
The Solution.
Representing the problem in a diagram, we have
By formula,

In this case,

Substituting these values in the formula above, we get

Clearing the bracket, we get



Dividing both sides by 2, we get

Therefore, the correct answer is option C.