Help please, finding the volume of a prism!

In the diagram below what is the approximate length of the minor arc ab

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 area of a parallelogram with the given vertices. p(-2, -5), q(9, -5), r(1, 5), s(12, 5)