Angles in triangle=180
180-102-31=47
x=47
Answer:
(x+11)(x-11)
Step-by-step explanation:
A ^2 - B ^2 =(A+B) (A-B).. (*)
x^2 - 121=
x^2 - 11^2=(*)
(x+11)(x-11)
Here is one x = 2 + 1/2 y
First you need to make a line that is perpendicular to one side. The diagram is shown below. then the length of the line that is perpendicular to the triangle is

then the area of the equilateral triangle equals to

so the area would be