Two sides of an equilateral triangle are 3x +15 and x + 21. Which of the following could be the measure of the third side?
What are your choices?
To find the measure of the third side of the equilateral triangle, we need to know that all sides of an equilateral triangle are equal in length.
Let's set up an equation using the given information.
Since two sides are given as 3x + 15 and x + 21, we can equate them:
3x + 15 = x + 21.
Now, let's solve this equation to find the value of x:
3x - x = 21 - 15,
2x = 6,
x = 3.
Next, we substitute the value of x back into one of the given sides to find the length of the third side:
Third side = x + 21 = 3 + 21 = 24.
Therefore, the measure of the third side could be 24 units.