Question

pls find the answer for 4 th question

Answer 1

Given, cos A=5/13 so b=5,h=13 and p=12
sinB=4/5 so p=4,h=5 and b=3
So,
$\sin(a + b) = \sin \: a \times \cos \: b + cos \: a \times sin \: b \\ = \frac{12}{13} \times \frac{3}{5} + \frac{5}{13} \times \frac{4}{5} \\ = \frac{36}{75} + \frac{20}{75} \\ = \frac{56}{75}$