Let's say Bailey takes "b" days to paint it.
and Andrew takes "a" days to paint the same house.
now, Andrew is 6 times faster than Bailey, therefore, if Andrew takes "a" days to do it, Bailey takes then "6a" days, or b = 6a.
now, the year they worked together, they finished it in 7 days.
so, after 1 day then, they have only done 1/7 of the whole work.
and Andrew for one day, has done 1/a of the house, whilst Bailey has done 1/b of the house or 1/(6a).

Answer:
triangles always add up to 180 degrees on the interior and because it has equal sides and angles, the triangle is equalateral.
According to your question the height for the triangle is 12inch