If the lengths of the sides of a triangle are in the ratio 3: 4 : 5 and its perimeter is 48 cm, find its area.

The base of a right angled triangle is 12 cm and its hypotenuse is 13 cm long. Find its area and the perimeter.

Find the area of an equilateral triangle whose side is 8 m. Give your answer correct to two decimal places.

If the perimeter of an equilateral triangle is 36 cm, calculate its area and height.