In the figure, the length of BC is 8.1 cm
How to work out the length of BC
The length of BC is solved as follows
Frist, solve for BD using Pythagoras
BD² = 7.5² + 5²
BD² = 56.25 + 25
BD = √81.25
BD = 9.01
Now using cosine rule we solve for BC
BC² = 13² + 9² - 2 * 9 * 13 * cos 38
BC² = 169 + 81 - 234 cos 38
BC= √(250 - 184.395)
BC = 8.1 cm