Answer:
10.1
Step-by-step explanation:
nearest possible answer
AC=10.1
2accosB=a²+c²-b²
2×7×13cos 50=7²+13²-AC²
182cos50=49+169-AC²
AC²=218-182 cos50
AC=√(218-182 cos 50)≈10.0505≈10.1