A triangle has a perimeter of 32.4 kilometres. Two of the sides measure 10.8 kilometres and 10.8 kilometres. What is the length of the third side?

10.8 kilometers

Step-by-step explanation:

Perimeter of a triangle equation is P (perimeter)= a+b+c

put 32.4 of the left side of the equation as it is the answer for the perimeter and replace and and b with your first 2 side legnths like this

32.4= 10.8+ 10.8+c

Now we must solve for the unknown side legnth c. To do this we must simplify the right side of the equation first by adding 10.8+ 10.8

32.4= 21.6+c

Now we can subtract 21.6 from the left side to solve for c

10.8=c

Therefore the third side is 10.8 kilometers

10.8 km

Step-by-step explanation:  A triangle has three sides:  a, b, and c

The perimeter is a+b+c and is a total of 32.4 km.   We know a=10.8 km and b = 10.8 km.

10.8 km + 10.8 km + c = 32.4 km

21.6km + c =  32.4 km

c = 10.8 km

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step-by-step explanation: