Question

The length of a rectangular room is 6.5 m in the width is 4.23 meters. What is the perimeter of the room? Report the answer with appropriate number of significant digits.
-21 meters
-21.5 meters
-21.46 meters
-21.460 meters

Answer 1

Perimeter is equal to 2l+2w, or 2 times the length plus 2 times the width. 

So to solve for this you'd take 2(6.5) + 2(4.23). 
2(6.5)= 13
2(4.23)= 8.46

13+8.46= 21.46 meters. 

Based on this, the answer is C.