# If #hatQ# is a Right-angle in #DeltaPQR and PR-PQ=9 , PR-QR=18# then what is the perimeter of the triangle?

##### 2 Answers

Perimeter is

#### Explanation:

As in right angled triangle

**.......................(A)**

Now let

and as

Putting these values in **(A)**, we have

or

or

or

or

or

Observe that as all sides are positive, we must have

and hence only solution is

and sides are

and perimeter is

Perimeter =

#### Explanation:

If

Let

Then

Write an equation using Pythagoras' Theorem:

If the hypotenuse is

Perimeter =