In the figure below, GRAH is a rectangle, RA = 7, and GA = 10. Determine AH.
Because it is a rectangle we know that GR = HA and we can work out GR with pythagoras as rectangles always have right angeled corners
Pythagoras = a^2 + b^2 = c^2
10^2= 100 7^2= 49
100-49 = 51
sqrt 51 you get 7.14