Answer:
70
Explanation:
The perimeter is the sum of the length of all the sides of a shape.
So, to find the lengths of the missing sides, use the lengths of the sides given.
One of the sides = 7 in. the other one = 8 in.
Then, add all sides:
10 + 10 = 20
7 + 8 = 15
15 + 20 = 35
17 + 18 = 35
35 + 35 = 70
So, the final answer is 70!