find the perimeter

Question

Find the perimeter, express your answer in simplified radical form. 

 

Find the perimeter of the rectangle. 

 

not sure how to put a rectangle on here, on the right side its √20 cm. and on the bottom of the rectangle its √320 cm. 

 

 

 

 

 

 

( the answer is 20√5 cm but i need help step by step on how they got this answer) 

Answer 1

Alright, Cathryn, let's do this thing.

 

Remember that √50 = √(25 x 2) =√25 x √2 = +5√2

 

The formula for the perimeter is 2l + 2w.

 

2√320 + 2√20 = 2√(64 x 5) + 2√(4 x 5) = 2(8)√5 + 2(2)√5 = 16√5 + 4√5 = 20√5

 

Make sense?