In a normal distribution, the median (I think you meant to say) is equal to the mean and mode.
To find the area of an obtuse triangle you have to multiply the base of the triangle by the vertical height and divide the result by 2 following the formula:
The base of the triangle is b= 7 miles and the height is h= 8 miles, using these lengths calculate the area as follows:
The area of the triangle is 28 square miles.