Question 755114
The lengths given are enough that you can calculate the area of the combined triangle halves, based on using (1/2)*{base}*{height}.   The area of the sector can be calculated easily knowing that the central angle is 90 degrees.  You want a difference of two areas.  For the sector, the area is a {{{(90/360)}}} of {{{pi*1^2}}} using 1 as the radius.


Do you recognize what kind of triangle you have there?


That's is as far as this solution is taken because you seem to be taking a test. You have now been given enough informative help.