Equilateral Triangle Perimeter Explained
An equilateral triangle is a triangle where all three sides are equal in length.
The perimeter of a shape is the total distance around its boundary. For a triangle, it's calculated by adding the lengths of all three sides.
Calculating the Perimeter
Since all sides of an equilateral triangle are equal, we can calculate its perimeter using a simple formula.
Let the length of one side of the equilateral triangle be '$s$'. The formula for the perimeter '$P$' is:
$P = s + s + s$
This can be simplified to:
$P = 3 \times s$
Step-by-Step Calculation
The question states that the side length of the equilateral triangle is 13 cm.
Given:
- Side length, $s = 13 \text{ cm}$
Now, substitute the value of '$s$' into the perimeter formula:
$P = 3 \times 13 \text{ cm}$
Performing the multiplication:
$P = 39 \text{ cm}$
So, the perimeter of the equilateral triangle is 39 cm.
Important Questions from Mensuration
- The volume of a wall that is 5 times as high as it is broad and 8 times as long as it is high is 12.8 cubic meters. Find the breadth of the wall.
- If the radius of a sphere is increased by 2 cm, then its surface area increases by 704 cm\(^2\). Using \(\pi = \frac{22}{7}\), find the radius of the sphere after the increase.
- The perimeter of a square is 76 m. Its area (in $m^2$) is:
- A cylindrical rod has an outer curved surface area of 1800 cm$^2$. If the length of the rod is 52 cm, then the outer radius (in cm) of the rod, correct to two places of decimal, is:
Take $\pi = \frac{22}{7}$ A spherical tank has a diameter of 10 metres. What is the volume of the spherical tank? (Use $\pi = 3.141$)
