Round 691 513 to the nearest thousand

The sixth grade art students are making a mosaic using tiles in the shape of right triangles.each tile has leg measures of 3 centimeters and 5 centimeters.i f there are 200 tiles in the mosaic what is the area of the mosaic.

Find the sum of the measure of the interior angles of a polygon of 9 sides ; of 32 sides

Select the lengths in centimeters that would form a right triangle