Use the Pythagorean Theorem to find the length of the side GJ, since the triangle GHJ is a right triangle.
Notice that the leg GH has a length of 4 units, while the leg HJ has a length of 3 units. According to the above mentioned theorem:
[tex]\begin{gathered} GJ^2=GH^2+HJ^2 \\ \Rightarrow GJ=\sqrt[]{GH^2+HJ^2} \end{gathered}[/tex]Substitute GH=4 and HJ=3 and solve for GJ:
[tex]\begin{gathered} \Rightarrow GJ=\sqrt[]{4^2+3^2} \\ \Rightarrow GJ=\sqrt[]{16+9} \\ \Rightarrow GJ=\sqrt[]{25} \\ \Rightarrow GJ=5 \end{gathered}[/tex]Therefore, the length of GH is equal to 5.
