How can you express 1/4 as a percent?

Which statement justifies why angle ebc measures 90?

Me n o w. i need t h i s. 10 points

This is a map of the mars exploration rover opportunity predicted landing site on mars. the scale is 1cm : 9.4km. what are the approximate measures of the actual length and width of the ellipse? i mostly need to know how to set it up : )