I am assuming you wrote the problem wrong. Is it a^2?
A^2 -4A-21=0
(A-7)(A+3)=0
A=7 A=-3, ignore the negative number because it doesn't make sense if you plug in for a.
length=a+3=7+3=10
Width=7=a
The area is 1,385,442
Hope that helps
Answer:
this is a 60 60 60 triangle, so one exterior angle is 120 degrees.
Step-by-step explanation:
hope it helps!
