Find the missing digits for the following tracking number 84200912█

The radius of the base of a cylinder is 10 centimeters, and its height is 20 centimeters. a cone is used to fill the cylinder with water. the radius of the cone's base is 5 centimeters, and its height is 10 centimeters.

If a || b and b | y, then ? a) x || y. b) x | a. c) a | y. d) a || y.

The measurement of one angle of a right triangle is 42° what is the measurement of the third angle? (there is no picture)