(Iready) I need you alot! plss

What is the maximum total area that 450cm of string can enclose if it is used to form perimeters of two adjoining rectangles as shown?

Astore sells two types of radios. one type sells $87 and the other for $119. if 25 were sold and the sales were $2495, how many of the $87 radios were sold a) 5 b) 20 c) 15 d)10

What happens to the area as the sliders are adjusted? what do you think the formula for the area of a triangle is divided by 2?