Answer:
2.7cm
Step-by-step explanation:
To find the answer, you would need to subtract the total perimeter by the 2 sides.
10.5cm - 4.6cm (side 1) = 5.9cm
5.9cm - 3.2cm (side 2) = 2.7cm
To prove this, all you would need to do is add up all three sides of the triangle to see if you get the perimeter.
4.6cm (side 1) + 3.2cm (side 2) + 2.7cm (side 3) = 10.5cm
Another way you could do this is by adding the two sides you were originally given, and subtracting them by the perimeter.
4.6cm (side 1) + 3.2cm (side 2) = 7.8cm
10.5cm (perimeter) - 7.8cm = 2.7cm
