Question

Among the following options, which one can not be the sides of right-angled triangle?
1. 20 cm, 21 cm, and 29 cm
2. 60 cm, 91 cm, and 109 cm
3. 39 cm, 80 cm, and 89 cm
4. 36 cm, 77 cm, and 84 cm
5.

Answer 1

Correct Answer - Option 4 : 36 cm, 77 cm, and 84 cm

Concept used:

A right-angled triangle follows the Pythagoras theorem

Hypotenuse² = Perpendicular² + Base²

Calculations:

Checking the given options for the Pythagoras theorem,

Option 1

⇒ 20² + 21² = 29²

It follows the Pythagoras theorem, thus these are the sides of a right-angled triangle

Option 2

⇒ 602 + 912 = 1092

It follows the Pythagoras theorem, thus these are the sides of a right-angled triangle

Option 3

⇒ 392 + 802 = 892

It follows the Pythagoras theorem, thus these are the sides of a right-angled triangle

Option 4

⇒ 362 + 772 ≠ 842

It doesn't follow the Pythagoras theorem, thus these are not the sides of a right-angled triangle

∴ 36 cm, 77 cm, and 84 cm are not the sides of a right-angled triangle