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Lesson Example Discussion Quiz: Class Homework

Lesson

Title: Perimeter of Triangle

Grade: 1300-a Lesson: S3-L3

Explanation: Hello Students, time to learn definitions. Let us take turns and read definitions and explain the pictures. Try to remember or memorize the definitions. Pay special attention to the pictures and communicate in your own words.

Lesson:

Definition: Perimeter Of Triangle

A triangle’s perimeter is the sum of its sides.
Equilateral triangles have 3 equal sides and angles.
Isosceles triangles have 2 equal sides.
Scalene triangles have 3 different side lengths.

$1$

Explanation: To find a triangle’s perimeter, add up its side lengths (a, b, c). For an equilateral triangle, multiply one side by 3. 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: Special Right Triangle

Special right triangles have unique properties that can be simplified using SOH-CAH-TOA.
In a right triangle, sin(θ) = \$("opposite")/("hypotenuse")\$, cos(θ) = \$("adjacent")/("hypotenuse")\$, and tan(θ) = \$("opposite")/("adjacent")\$.
Remember, the hypotenuse is opposite the right angle and is the longest side, while the adjacent side is next to the angle θ.

$2$

Explanation: In this image, it shows sinA = \$"a"/"c"\$, cosA = \$"b"/"c"\$ and tanA = \$"a"/"b"\$.