In geometry, the definition of a triangle is a two-dimensional closed figure with three sides. Aside from this, it is proven that the sum of the angles of a triangle is 180°. This is a triangle's innate property. Therefore, any closed shape with three sides is a triangle and it follows that the sum of the three angles is equal to 180°.

It is logical therefore, that the first step in proving this is by using the definition of a triangle.

6 0

2 years ago

Pls helpppp meeeeee :(

Alja [10]

Answer:

Sam

Step-by-step explanation:

Sam made a mistake when he said $10^2 -20$ . The steps should have been:

$2n^2-20=2(5)^2-20\\2(25)-20\\50-20=30$

You are supposed to square 5 first before multiplying 2. Sam multiplied by 2 first. The correct answer is 30.

7 0

2 years ago