the perimeter of an isosceles triangle whose base is 11cm is 39. one of the equal sides of the triangle will be:
A 11cm B 9cm C 14cm D 12cm
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What do you think?
14
To solve this problem, we can use the formula for the perimeter of a triangle. The perimeter of a triangle is the sum of the lengths of all three sides.
In this case, we know that the base of the triangle is 11 cm and the perimeter is 39 cm. Since it is an isosceles triangle, it means that two sides are equal in length. Let's denote the length of each equal side as "x".
The perimeter of the triangle can be written as:
Perimeter = base + equal side + equal side
39 = 11 + x + x
39 = 11 + 2x
Now, we can solve for x by subtracting 11 from both sides of the equation:
39 - 11 = 11 + 2x - 11
28 = 2x
Dividing both sides of the equation by 2, we get:
28/2 = 2x/2
14 = x
Therefore, one of the equal sides of the triangle is 14 cm.
So, the answer is: C) 14cm