SaiBook.us Math

Home Course Section Lesson

Lesson Topics Discussion Quiz: Class Homework

Definition1

Title: Perimeter of Traiangle

Grade Lesson s4-l3

Explanation: The best way to understand PSAT-4 is by looking at some definitions. Take turns and read each definition for easy understanding.

Definition

Topics → Definition Example1

Definition: Perimeter of Triangle

The perimeter of a triangle is defined as the sum of the lengths of its three sides.

In mathematical terms, if a triangle has sides of lengths a, b, and c, then the perimeter P is given by: p = a + b + c

$1$

Explanation:

In this image, the perimeter of a triangle is 40cm given the lengths of its sides as 15cm, 18cm and 7cm.

Definition: Equilateral Triangle

An equilateral triangle is a type of triangle where all three sides are of equal length.

Additionally, all three angles in an equilateral triangle are also equal, each measuring 60 degrees.

$2$

Explanation:

For an equilateral triangle, multiply one side by 3.

Definition: Isosceles Traiangle

An isosceles triangle is defined by two equal sides and two equal angles opposite those sides.

This means a triangle typically contains two equal sides and two equal angles.

$3$

Explanation:

To find a triangle’s perimeter, add up its side lengths (a, b, c). For isosceles triangles, add 2 times the length of one side (a) to find the third side (c). Remember, a, b, and c are side lengths.

Definition: Scalene Traiangle

A scalene triangle is a type of triangle in which all three sides have different lengths.

Additionally, the angles opposite these sides are also of different measures.

$4$

Explanation:

I need to find the perimeter of a scalene triangle. The lengths of its sides are 5 cm, 3 cm, and 2 cm, and the total perimeter of the triangle is 10 cm.