Use cosine rule,
cos(A)=(b^2+c^2-a^2)/(2bc)
=(10^2+12^2-6^2)/(2*10*12)
=13/15
A=29.926 degrees.................................(A)
cos(B)=(c^2+a^2-b^2)/(2ca)
=(12^2+6^2-10^2)/(2*12*6)
=5/9
B=56.251 degrees.................................(B)
cos(C)=(a^2+b^2-c^2)/(2ab)
=(6^2+10^2-12^2)/(2*6*10)
=-1/15
C=93.823 degrees.................................(C)
Check:29.926+56.251+93.823=180.0 degrees....ok
Answer:
Step-by-step explanation:
(a+b)^2=a^(2)+2ab+b^(2)
(a-b)^2=a^(2)-2ab+b^(2)
13)
(x+2)^(2)-(x-1)^2
x^(2)+4x+4-(x^(2)-2x+1)
x^(2)+4x+4-x^(2)+2x-1
6x+3
15)
(x+5)^(2)-(x+1)^2
x^(2)+10x+25-(x^(2)+2x+1)
x^(2)+10x+25-x^(2)-2x-1
8x+24
After plotting all the points, the only one that makes sense is (4,3).
