Question

5. The sides of a triangle measure 15 cm, 36 cm and 39 cm. Show that it is a right-angled
triangle.
Hint. (39)2 – (36)2 = (39+36)(39-36) = (75x 3) = (5x5x3x 3) = (5x3)2 = (15) .​

Answer 1

Answer:

As we know that, in a right triangle, square of the hypotenuse is equal to the sum of square of the other two sides.

Therefore,

(39)

2

=(36)

2

+(15)

2

1521=1296+225

⇒1521=1521

L.H.S. = R.H.S.

Hence the triangle is right-angled triangle.

Answer 2

As we know that, in a right triangle, square of the hypotenuse is equal to the sum of square of the other two sides.

Therefore,

(39)²=(36)²+(15)²

1521=1296+225

⇒1521=1521

L.H.S. = R.H.S.

Hence the triangle is right-angled triangle.

verified.