The lengths of the rectangle have been measured to the nearest tenth of a metre. Work out the following, writing down all the figures on your calculator display:
the upper bound for the perimeter of the rectangle
the lower bound for the area of the rectangle
length - 15.8m
width - 5.2m

Perimeter (upper bound) =42.16 m

Area (lower bound)= 81.11 m2

Step-by-step explanation:

Hi, to answer this question we have to analyze the information given:

Since both measures were rounded to the nearest tenth, the possible numbers are:

Length (L) =15.8m ; (between 15.75 and 15.84)

Lower =15.75 ; upper = 15.84

Width (w) =5.2m (between 5.15 and 5.24)  

Lower = 5.15 ; upper = 5.24

Upper bound perimeter = 2 (15.84)+2(5.24) = 42.16 m

Lower bound for the area of the rectangle = 15.75 x 5.15 = 81.11 m2

Feel free to ask for more if needed or if you did not understand something.  

check the picture below.

well, the angle at the vertex d is clearly not a right-angle, let's check for the one at the vertex f which does look like,   however if it's indeed, that means ef is perpendicular to df, in which case their slopes will be negative reciprocal of each other.

so the negative reciprocal of the slope of ef is 1, however the slope of df is not 1, is 1/2, so nope, they're not perpendicular lines.