Do you have enough information to work out the area of the shaded quadrilateral?
Three equilateral triangles ABC, AYX and XZB are drawn with the point X a moveable point on AB. The points P, Q and R are the centres of the three triangles. What can you say about triangle PQR?
Find the positive integer solutions of the equation (1+1/a)(1+1/b)(1+1/c) = 2