How do you write 0.0000005051 in scientific notation?

Find the slope of a line given the following two points

Acircular garden with radius of 8 feet is surrounded by a circular path with a width of 3 feet. what is the approximate area of the path alone? use 3.14 for π

In the picture below, line pq is parallel to line rs, and the lines are cut by a transversal, line tu. the transversal is not perpendicular to the parallel lines. note: figure is not drawn to scale. which of the following are congruent angles?