Question

Find the interior angle A of the triangle with vertices A(1, 5), B(3, -1), and C( -1, -1).

Answer 1

you know cosine formula ??

Answer 2

\[c^2=a^2+b^2-2ab*Cos(y)\]

Answer 3

y is interior angle and a,b,c are the sides of triangle

Answer 4

you have vertices using distance formula calculate length of sides of triangle

Answer 5

you will find a,b and c from here

Answer 6

good luck :)

Answer 7

THANK YOU! :)