Question

two sides of a triangle are 5cm and 4cm. the perimeter of the triangle is 12cm. find the length of third side.​

Answer 1

Answer:

perimeter= L+b+ h

12= 5+4+h

12-9= h

3=h

height= 3cm

Step-by-step explanation:

hope it helps you

Answer 2

Answer:

Third Side (Height) of ∆ABC = AB = 3 cm

Step-by-step explanation:

First Side (Hypotenuse) = AC = 5cm

Second Side (Base) = BC = 4 cm

Perimeter of ∆ABC = 12 cm

By applying the formula for Perimeter of Triangle,

Perimeter of ∆ABC = AB + BC + AC

12 = AB + 4 + 5

12 = AB + 9

AB = 12 - 9

So, AB = 3 cm

[Note : If ∆ABC was a right-angled triangle at B, then we must have found the Third Side by Pythagoras Theorem too.]