The symbol used to seperate the tenths and ones is called a?

What is the perimeter of trapezoid jklm? + units 2 + + units 9 + units 9 + + units

How do you use the elimination method for this question? explain, because i really want to understand!

The length of a shadow of the building is 36m. the length of the pole, which is perpendicular to the ground, is 1.9m. the length of the pole's shadow is 1.52m. what is the height of the building?