Type the correct answer in the box. use numerals instead of words. if necessary, use / for the fraction bar. ab is parallel to cd, and ef is perpendicular to ab. the number of 90 degree angles formed by the intersections of ef and the two parallel lines ab and cd is

8

If EF is a line perpendicular to  AB, then it forms four (90 degrees) angles intersecting AB. If AB is parallel to CD, and EF also intersects CD, then it form another four (90 degrees angles again. Total 90 degrees angles formed is 8.

20: 5

explanation:

about 20% of the world's population lives in   southwest asia, but on less than 5% of the world's   land area.