Question #e2f2f

1 Answer
Jan 6, 2018

25 ft wire is attached to the ground at color(blue)(8.75 ft) from the base of the pole.

Explanation:

enter image source here

I’m using a figure, available on the net, that is somewhat relevant to this sum. All the measurements labeled in the figure may be ignored.

Given
BC = 30 ft, BD = 25 ft, DC = 10 ft

Let AD = x, AB = y

To find ‘x’

AB^2 = BD^2 + AD^2

y^2 = 25^2 - x^2

y^2 + x^2 = 625. Eqn (1)

AB^2 = BC^2 + AC^2 = BC^2 + (AB + DC)^2

y^2 = 30^2 - (x + 10)^2

y^2 + x^2 + 20x = 30^2 - 10^2 = 800 Eqn (2)

Substituting Eqn (1) from Eqn(2),

cancel(y^2 + x^2) + 20x - cancel(y^2 + x^2) = 800 - 625

20x = 175 or x = 175/20 = 8.75 ft

25 ft wire is attached to he ground at 8.75 ft from the base of the pole.