If the perimeter of a triangle is 30 cm and the lengths of two sides are 10 cm a

₹0.0

Question: If the perimeter of a triangle is 30 cm and the lengths of two sides are 10 cm and 12 cm, what is the length of the third side? (2020)

Options:

Correct Answer: 8 cm

Exam Year: 2020

Solution:

Let the third side be x. Then, 10 + 12 + x = 30, so x = 30 - 22 = 8 cm.

If the perimeter of a triangle is 30 cm and the lengths of two sides are 10 cm and 12 cm, what is the length of the third side? (2020)

If the perimeter of a triangle is 30 cm and the lengths of two sides are 10 cm and 12 cm, what is the length of the third side? (2020)

Step 1: Write down the formula for the perimeter of a triangle, which is the sum of all three sides.
Step 2: Identify the lengths of the two known sides. In this case, they are 10 cm and 12 cm.
Step 3: Let the length of the third side be represented by 'x'.
Step 4: Set up the equation for the perimeter: 10 cm + 12 cm + x = 30 cm.
Step 5: Combine the known side lengths: 10 + 12 = 22.
Step 6: Rewrite the equation with the combined side lengths: 22 + x = 30.
Step 7: To find 'x', subtract 22 from both sides of the equation: x = 30 - 22.
Step 8: Calculate the value of 'x': x = 8 cm.

Perimeter of a Triangle – Understanding that the perimeter is the sum of all sides of a triangle.
Algebraic Manipulation – Solving for an unknown variable in a simple equation.