What is the value for "C" in the equation x^{2} +3x-6=0

it is not that hard all u have to do is plot the graph

step-by-step explanation:

m∠5 + m∠3 = m∠1   is true.

m∠5 + m∠6 = 180 is true

m∠2 +m∠3 = m∠6   is true

m∠2 +m∠3 +m∠5 = 180   is true