i) Perimeter of a scalene triangle = (7 + 8 + 10) m = 25 m
ii) The three sides of the isosceles triangle are 10 cm, 10 cm and 7 cm
∴ Perimeter = (10 + 10 + 7) cm = 27 cm
iii) An equilateral triangle with side 6 cm.
The sides of equilateral triangle are 6 cm, 6 cm and 6 cm
∴ Perimeter = (6 + 6 + 6) cm = 18 cm