The 3 angles need to equal 180 when added together:
A) 49 + 59 +72 = 180
The others do not equal 180
Answer: The answer for this is "The three sides have the same length."
Because its a equilateral triangle (we know this because all the angles are 60 degrees) all the sides are equal.
<h2>8 unit tiles should be added</h2>
Step-by-step explanation:
Function given is
. We wish to add more unit tiles to the function so that it becomes a complete square.
Since the given function is of order 2, the side of the square will be order 1. Let us assume a general order 1 expression
to be the side of the square.
As the function forms the square after adding some
unit tiles, 

From comparision, 
∴ 8 more unit tiles are required to complete the square.
Answer:

Step-by-step explanation:
To prove the given identity, we solve the left hand side and right hand side expressions and show that they are equal.
So we get

check by plugging into both equations
-8+4(3)=4
-8+12=4
4=4
-8+3(3)=1
-8+9=1
1=1
(8,3) is a solution of the system