I NEED help with this ASAP

What is the simplified form of square root of 400 to the 100th power ?

Atriangle has side lengths of x, x+11, and 3x+5. what is the perimeter?

Points j and k plotted on the coordinate grid are two vertices of rectangle jklm rectangle jklm has an area of 7 square units point j is located at 2,1 and point k is located at -5,1 each vertex of the rectangle is located at a point that has integer coordinates. what is the perimeter of rectangle jklm? (need answer asap)