SaiBook.us Geometry

Lesson Example Discussion Quiz: Class Homework

Example

Title: Perimeter of Triangle

Grade: 6-a Lesson: S1-L7

Explanation: The best way to understand geometry is by looking at some examples. Take turns and read each example for easy understanding.

Examples:

A triangle has sides measuring 15 cm, 5 cm, and 10 cm.If the longest side is reduced by half, what is the new perimeter of the triangle ?

Step 1a

The sides of a triangle is given 15 cm , 5 cm , 10 cm.

$1a$

Explanation: The measurements of the sides of a triangle are 15 cm, 5 cm, and 10 cm.

Step 1b

The longest side length is 15 cm.

If you reduce the length of the longest side by half \$15/2\$ = 7.5

Explanation: The length of the longest side is 15 cm, and if you reduce it by half, it becomes 7.5 cm.

Step 1c

Now, to find the new perimeter of the triangle, you need to add up the lengths of all three sides with the updated length of the longest side: Perimeter = a + b + c

New Perimeter = 7.5 + 5 + 10 is 22.5 cm

Explanation: To determine the new perimeter of the triangle, Therefore, the formula for the perimeter is P = a + b + c.In this case, the new perimeter would be 7.5 + 5 + 10, which is equal to 22.5 cm.

Step 1d

So, the new perimeter of the triangle, with the longest side reduced by half, is 22.5 cm.

Explanation: After reducing the longest side by half, the new triangle perimeter is 22.5 cm.