Question Video: Identifying Algebraic Expressions | Nagwa Question Video: Identifying Algebraic Expressions | Nagwa

# Question Video: Identifying Algebraic Expressions

The side length of an equilateral triangle is πΏ and its perimeter is π. What is the mathematical relation between π and πΏ? [A] π = πΏ + 3 [B] π = πΏ β 3 [C] π = 3πΏ [D] π = 1/3 πΏ. What is the term used to describe πΏ in π? [A] A variable [B] A constant

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### Video Transcript

The side length of an equilateral triangle is πΏ and its perimeter is π. What is the mathematical relation between π and πΏ? Is it (A) π equals πΏ plus three. (B) π equals πΏ minus three. (C) π equals three πΏ. Or (D) π equals one-third πΏ. What is the term used to describe πΏ in π? Is it (A) a variable or (B) a constant?

An equilateral triangle has three sides of equal length. In this question. We are told theyβre of length πΏ. The perimeter of any shape is the distance around the outside. This means that π is equal to πΏ plus πΏ plus πΏ. This simplifies to three πΏ. We can calculate the perimeter of any equilateral triangle by multiplying its side length by three. The correct one of our answers is option (C) π is equal to three πΏ. We can use this equation to calculate the perimeter of any equilateral triangle when given the side length.

The second part of our question wants us to decide whether the term πΏ is a variable or a constant. A constant term will be one that never changes, for example, the positive three in option (A) and the negative three in option (B). A variable, on the other hand, will change or alter. As πΏ is the side length of the equilateral triangle, this will vary depending on the size of the triangle. And πΏ is therefore a variable. The correct answer is option (A). In the equation π is equal to three πΏ, πΏ is a variable and three is the coefficient of πΏ.

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