Answer:
10.2cm
Explanation:
Perimeter is the sum of the lengths of all sides.
1st side: 9cm
2nd side: 7.8cm
Perimeter: 27cm
Perimeter = 1st + 2nd +3rd side of a triangle
27cm = 9cm +7.8cm + 3rd side
3rd side = 27cm - 9cm -7.8cm
= 10.2cm
1.6m questions
2.0m answers