Question

Find the value of '$x$' in the below given figure.

• A. 4 cm
• B. 8 cm
• C. 12 cm
• D. 1 cm

Answer 1

The correct option is B 8 cm

Given, $\Delta$ ABD is a right angled triangle.
From pythagoras theorem,
$A{D}^2+B{D}^2=A{B}^2$
$\Rightarrow {0.9}^2+B{D}^2={4.1}^2\Rightarrow 0.81+B{D}^2=16.81\Rightarrow B{D}^2=16\Rightarrow BD\times BD=4\times 4\Rightarrow BD=4$
Similarly from the triangle $ADC$ we get $DC=4cm$
So, $x=BC=BD+DC=4+4=8cm$