Question

Find the value of AD in the given figure.


[3 Marks]

Answer 1

In a right $△ABC$ using Pythagoras theorem we have,
$A{C}^2=A{B}^2+B{C}^2$
$\Rightarrow A{C}^2=3^2+4^2$
$\Rightarrow A{C}^2=25$
$\Rightarrow AC=5m$

[1.5 Marks]

In a right $△ACD$ using Pythagoras theorem, we get,
$A{D}^2=A{C}^2+C{D}^2$
$\Rightarrow A{D}^2=5^2+{12}^2$
$\Rightarrow A{D}^2=25+144\Rightarrow A{D}^2=169\Rightarrow AD=13m$.

[1.5 Marks]