i got the answer to be 102.6 metres.Swalbs said:Instead of agreeing that its 0.1, do you think one of you could post HOW you got the answer?

First you had ti find the distance PT (using pythagoras with the other two sides) which equalled 2050. Then I 'looked' from above, and drew a diagram of an isosceles triangle with height PT and base 2r. Because of the line down the middle, you have two right angle triangles, with sides r and PT. you are given the acute angle 0.1/2 (you have to divide by two because alpha is the total angle, and you just want half). Then tan (a/2) = r/PT

r=tan(0.1/2).2050

=102.6m