1.38: Past-paper question 3

4PM1/1/November/2024 — Question 3 · 5 marks

Triangle ABC\displaystyle ABC is such that
AC=10cmAC = 10 \mathrm{cm}
BC=7cmBC = 7 \mathrm{cm}
angleCAB=25∘\mathrm{angle} CAB = 25^\circ
Given that angle ABC\displaystyle ABC is obtuse,
find, in cm to one decimal place, the length of AB\displaystyle AB
(5)