What is the correct equation in vertex form for x^2+4x-12=0

An arc subtends a central angle measuring 7pi/4 radians what fraction of the circumference is this arc?

The architect's side view drawing of a saltbox-style house shows a post that supports the roof ridge. the support post is 8 ft tall. the distance from the front of the house to the support post is less than the distance from the post to the back of the house. how far from the front of the house is the support post positioned?

Typically a point in a three dimensional cartesian coordinate system is represented by which of the following answers in the picture !