Find the central angle of a sector of a circle if the area of the sector and the area of the remaining part of the circle are in the proportion 4 : 5 ( with explanation )

Mat bought a phone for $100. he has to pay $30 per mouth. if he has paid $640 in total, how many mouth has he had the phone?

5x−4≥12 or 12x+5≤−4 can you with this problem

Consider the triangle. which shows the order of the angles from smallest to largest? angle a, angle b, angle c angle b, angle a, angle c angle b, angle c, angle a angle c, angle a, angle b