Answer:
I) 8x12=96cm^2
Probably 96.0 to 2 s.f
II)8.3x12.5=103.75cm^2
so it's 103.8cm^2 to 1 d.p and 100 to 2 s.f
Perimeter
I) 8cm
Lower bound is 7.5
Higher bound is 8.5
12cm
Lower bound is 11.5 and upper bound is 12.5
Ans:
Lower first -
(7.5 x 2) + (11.5 x 2) = 38cm
To 2 s.f is 38.0cm
Higher next -
2 x (8.5+12.5)= 42cm
To 2 s.f is 42.0cm
Perimeter
II)8.3cm x 12.5cm(1 decimal place)
1d.p is 0.1
0.1/2 =0.05
8.3
Lowest is 8.25cm (8.30 - 0.05)
Highest is 8.35cm (8.30 + 0.05)
12.5
Lowest is 12.45cm (12.50 - 0.05)
Highest is 12.55cm (12.50 + 0.05)
Ans:
Lower first -
2 x (8.25+12.45) = 41.4cm
To 2 s.f is 41.0cm
Higher next -
2 x (8.35+12.55) = 41.8cm
To 2 s.f is 42.0cm
Hope this helps!
