In 1980 when the consumer price index was 82.4, ivan purchased a house for 71,900 assuming that the prices of the houses increased at the same rate as the cpi from 1970 to 1980 approximately how much would the house have cost in 1970 when the cpi was 38.8?

step-by-step explanation:

rectangles are made up of 4 right angles, which means that a side and a base meet perpendicular to one another.   their slopes then have to reflect perpendicular slopes.   perpendicular slopes are opposite reciprocals of one another.   for example, if the slope of one line is +2/3, then the perpendicular slope to that would be -3/2.   so we look for that combination in our choices.

all of them satisfy that condition (so what's the question, i guess? )