Rounded to the nearest whole number it would be 13
He needs it 4 inches longer because 4 ft is 48 inches.
Moving from a to b, the x component of the desired vector is 7-(-9) = 16, and
the y component is 3-9 = -6.
So the vector from a to b is <16,-6>, and the magnitude is
sqrt(16^2 + (-6)^2 ), applying the Pythagorean Theorem.
In the field of astronomy, the ability to measure angles accurately and precisely enables us to calculate the position and relative movement of the stars and galaxies in relation to each other, to determine how far distant they are from us, and even to estimate their relative size.
