Answer:
8.1
Step-by-step explanation:
Use Pythagoras to find the length of BD- 7.5^2 +5^2=81.25
The square root of 81.25 is 9.01
BD-9.01 cm
Then use the cos rule to find BC.
c=a2+b2﹣2abcosγ=9.012+132﹣2·9.01·13·cos(38°)≈8.09819(square root)
round to 8.1
