What number is represented by the point B which represents the number 2

Two sides of a triangle mesure 20cm and 30cm. what is the measure of the third side

Given the box plot, will the mean or the median provide a better description of the center? box plot with min at 10.5, q1 at 11.5, median at 12.5, q3 at 13.5, max at 15

Given the two similar triangles, how do i find the missing length? if a=4, b=5, and b'=7.5 find a'