Question

The perimeter of a triangle is 50 cm. If two of its sides are 15 cm and 20 cm long, find the length of the third side. If the perimeter of a square is 80 cm, find the length of its sides

Answer 1

Given that the perimeter of the triangle = 50 cm and the lengths of two sides are 15 cm and 20 cm
Since, perimeter of a triangle = sum of all sides
⇒ 15 cm + 20 cm + third side = 50 cm
⇒ 35 cm + third side = 50 cm
⇒ third side = 50 cm − 35 cm
⇒ third side = 15 cm.
Hence, the length of the third side = 15 cm