Can someone please help me I really need help

6.3

Step-by-step explanation:

If you cut a line through a rectangle diagonally, you form two right triangles.  Since you have a right triangle, you can use the Pythagorean Theorem.  The diagonal line will be the hypotenuse, and the width will be one of the legs.

a² + b² = c²

(3)² + b² = (7)²

9 + b² = 49

b² = 40

b = √40

b = 6.3

The length of the envelope is 6.3 inches.

the discriminant is 64 + 4*1*12 = 112

this is prime.

step-by-step explanation:

konichiwa~! my name is zalgo and i am here to answer your anime-related question today. more than likely, kirishima would kill izuku, marry mino and kiss momo. all of this would be my opinion by the way. (and i am also a weeb lol)

i hope this you! : d

stay and stay proud! " - zalgo

(and do you think you can mark me as brainliest? i'd greatly appreciate it! arigato~! )