Answer :

heyDB
To find the distance between two 3d pointssquare the difference of the x, y, and z points. Then, sum them and take the square root.
Distance=(x2x1)^2+(y2y1)^2+(z2z1)^2

Replace x^1,x^2,y^1,y^2,z^1, and z^2 with the corresponding values.
Distance=((5)−(7))^2+((2)−(2))^2+((9)−(4))^2

Simplify 
√((5)−(7))^2+((2)−(2))^2+((9)−(4))^2
calculator....

Distance= √29


The distance between (7,2,4) and (5,2,9) is 29.

√29≈5.38516481