The interior angles of a simple (and planar) quadrilateral ABCD add up to 360 degrees of arc, that is. This is a special case of the n-gon interior angle sum formula (n â 2) Ã 180Â°. All convex quadrilaterals tile the plane by repeated rotation around the midpoints of their edges.
1 CostHelper readers report paying $150-$300 for a windshield replacement, at an average cost of $214. 2  WindshieldsToGo.com provides an online form to estimate the cost of windshield replacement with and without installation, based on zip code and the year, make, model and style of vehicle.
Cost of a new windshield. Delaney says the average cost of a new windshield is about $255, including labor. âIt depends on the year, make and model,â Dennis Caswell, owner of Glas Tek Windshield Repair in St. Louis, says of the cost. âThose are the biggest factors. They can start from $200, but the skyâs the limit.â