Answer:
B = 12.8 cm (to 1.d.p)
D = 24.1 cm (to 1.d.p)
Explanation:
Using Pythagoras Theorem:
B: 4^2 + 3.5^2 = 28.25
square root 28.25 = 5.3 (to 1 decimal place) so this is the length of the missing side.
To find perimeter add sides a, b and c so...
perimeter of triangle B = 12.8 cm (to 1 decimal place)
D: 10^2 - 6.5^2 = 57.75
square root 57.75 = 7.6 (to 1 decimal place) so this is the length of the missing side.
To find perimeter add sides a, b and c so...
perimeter of triangle D = 24.1 cm (to 1 decimal place)
^2 indicates squared
Sorry but I'm not too sure / confident about A or C