Question

need help

Answer 1

u need to use pythagoras theorm here
in \(\triangle ADB\)

\(\angle ADB =90\)

so

\(\large\tt \begin{align} \color{black}{AD^2+BD^2=AB^2\\~\\
4^2+BD^2=5^2\\~\\
16+BD^2=25\\~\\
BD^2=25-16\\~\\
BD^2=9\\~\\
BD=\sqrt{9}\\~\\
BD=3\\~\\
}\end{align}\)
so




now u need to use pythagoras theorm
in \(\triangle BCD\)

\(\angle BCD =90\)

so

\(\large\tt \begin{align} \color{black}{BC^2+DC^2=BD^2\\~\\
BC^2+1^2=3^2\\~\\
BC^2+1=9\\~\\
BC^2=9-1\\~\\
BC^2=8\\~\\
BC=\sqrt{8}\\~\\
BC=\sqrt{4\times 2}\\~\\
BC=2\sqrt{ 2}\\~\\
BC=2.82\\~\\
}\end{align}\)