+2 votes
in Class 10 by kratos

Sides of triangles are given below. Determine which of them are right triangles. In case of a right triangle, write the length of its hypotenuse.

(i) 7 cm, 24 cm, 25 cm,

(ii) 3 cm, 8 cm, 6 cm.

(iii) 50 cm, 80 cm, 100 cm.

(iv) 13 cm, 12 cm, 5 cm.

1 Answer

+4 votes
by kratos
 
Best answer

In ⊥∆ABC, ∠B = 90°.

Let AB = a, BC = b,

Hypotenuse AC = c then

AC2 = AB2 + BC2

c2 = a2 + b2

∴ Here diagonal is the greatest side.

(i) a, b,c

7 cm, 24 cm, 25 cm,

c2 = a2 + b2

252 = (7)2 + (24)2

625 = 49 + 576

625 = 625

625 = 49 + 576

625 = 625

∴ This is right angled triangle.

Measurement of Hypotenuse, c = 25 cm.

ii) a c b

3 cm, 8 cm, 6 cm.

c2 = a2 + b2

82 = (3)2 + (6)2

64 = 9 + 36

64 ≠ 45

∴ These are not sides of right angled triangle.

iii) a b c

50 cm, 80 cm, 100 cm.

c2 = a2 + b2

1002= (50)2 + (80)2

10000 = 2500 + 6400

10000 ≠ 8900

∴ These are not sides of right angled triangle.

iv) a b c

12 cm, 5 cm, 13 cm,

c2 = a2 + b2

132 = (12)2 + (5)2

169 = 144 + 25

169 = 169

∴ These are sides of right angled triangle.

Measurement of Hypotenuse =13 cm.

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