The perimeter of a right-angled triangle is 60cm and its hypotenuse is 26cm. Find the other two sides.
Given perimeter of right-angled triangle is 60 cm.
hypotenuse = h = 26 cm
Let the other two sides be a & b.
So, a + b + h = 60
⇒ a + b = 60 – 26
⇒ a + b = 34 ...... (i)
By Pythagoras theorem,
⇒ a2 + b2 = h2
(As shown below:
⇒ a2 + b2 = 262
⇒ (a + b)2 – 2ab = 676
⇒ 342 – 2ab = 676
⇒ 2ab = 1156 – 676
⇒ 2ab = 480
⇒ ab = 240
Using (a – b)2 = a2 + b2 – 2ab
⇒ (a – b)2 = 676 – 2x240
⇒ (a – b)2 = 676 – 480
⇒ (a – b)2 = 196
⇒ a – b = 14 ...... (ii)
adding (i) &(ii);
⇒ 2a = 48
⇒ a = 24
⇒ b = 10
So, the other two sides are 24 cm & 10cm.