Josh's dad is 36 in tall when he measured the dust using a yardstick it was one yard tall why did the number decrease when he measured with the yardstick

Step-by-step explanation:

1 yard=3 ft=3*12=36 inch

so both are same only units are different.

check the picture below.

well, the angle at the vertex d is clearly not a right-angle, let's check for the one at the vertex f which does look like,   however if it's indeed, that means ef is perpendicular to df, in which case their slopes will be negative reciprocal of each other.

so the negative reciprocal of the slope of ef is 1, however the slope of df is not 1, is 1/2, so nope, they're not perpendicular lines.