John M. answered 05/26/21
Math Teacher/Tutor/Engineer - Your Home, Library, MainStreet or Online
I interpreted this as Jack couldn't be standing under the shadow of the tree or he wouldn't cast a shadow, but is 6 meters to the side.
The sun would be at the upper right of this diagram.
So 2:4, Jack's height : shadow length as X:2X for the tree's height:shadow length.
We don't know how tall the tree is, but can measure the tree's shadow length.
So the tree is 1/2 the shadow length.