1.

The hypotenuse of a right triangle is \(3\sqrt{10}\) cm. If the smaller leg is tripled and the longer leg doubled, new hypotenuse will be \(9\sqrt{5}\) cm. How long are the legs of the triangle

Answer»

Let the smaller leg be ‘a’ and longer leg be ‘b’.

Hypotenuse2 = length2 + breadth2

Given, hypotenuse of a right triangle is \(3\sqrt{10}\) cm

⇒ 9 × 10 = a2 + b2 

⇒ a2 + b2 = 90 -------- (1)

Now, the smaller leg is tripled and the longer leg doubled, new hypotenuse is \(9\sqrt{5}\) cm.

⇒ (3a)2 + (2b)2 = 81 × 5

⇒ 9a2 + 4b2 = 405 -------- (2)

Multiplying (1) by 4 and subtracting from eq 2

⇒ 5a2 = 45 

⇒ a2 = 9 

⇒ a = 3 

Thus, 9 + b2 = 90 

⇒ b2 = 81 

⇒ b = 9



Discussion

No Comment Found