Question

Find the value of $x$ and $y$. (Use Pythagoras theorem).

• A. $x=12$ and $y=3$
• B. $x=10$ and $y=5$
• C. $x=12$ and $y=5$
• D. $x=11$ and $y=5$

Answer 1

Answer: (C)

$x=12$ and $y=5$

In a right triangle, $a^2+b^2=c^2$, where a and b are the lengths of the legs and c is the length of the hypotenuse. This is called Pythagoras Theorem.
$a=3,b=4,c=$ hypotenuse side $=y$
$3^2+4^2=c^2$
$9+16=$ $c^2$
$c^2$ $=25$
Taking root on both the sides, we get
$c=5=y$
So, $x^2+y^2={13}^2$
$x^2+5^2={13}^2$
$x^2=169-25$
$x^2=144$
$x=12$
So, the value of $x=12$ and $y=5$.