Hey there! I'm happy to help!
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WHAT IS THE PERIMETER?
The perimeter is just the distance around a shape. If you put a fence around a field, the length of all of the fencing is the perimeter.
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WHAT IS AN ISOSCELES TRIANGLE?
An isosceles triangle is a triangle that has at least two sides that have the same length! In our triangle, we have two sides that have the value of a, so that makes it isosceles!
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THE SOLUTION
In our problem, we want to find the perimeter of this triangle in terms of a and c. When we say in terms of, it just means that our answer will include a and c instead of finding a number value.
The perimeter is the sum of each of these sides. This means that the perimeter is a+a+c, which is also 2a+c.
Therefore, the perimeter of this isosceles triangle is 2a+c.
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I hope that this helps! Have a wonderful day! :D
