Question

The telephone cable in the illustration currently runs from A to B to C to D.How much cable ( in yards) is required to run from A to D directly? yd

Answer 1

Given

$\begin{gathered} A\text{ to B =106 yd} \\ B\text{ to C= 72yd} \\ C\text{ to D=48 yd} \end{gathered}$

Solution

$\begin{gathered} P\text{ to D = 106+48} \\ P\text{ to D =154} \end{gathered}$

So to find A to D directly, We use pythagoras

$\begin{gathered} AD^2=154^2+72^2 \\ AD^2=23716+5184 \\ AD^2=28900 \\ Take\text{ the square root of both sides} \\ AD=\sqrt[]{28900} \\ AD\text{ =170 } \end{gathered}$

The final answer

170 yd is required to run from A to D directly