JAMB - Mathematics (2023 - No. 42)
Calculate, correct to three significant figures, the length AB in the diagram above.
36.4 cm
36.1 cm
36.2 cm
36.3 cm
Explicaţie
\(\frac {\sin A}{a} = \frac {\sin B}{b} = \frac {\sin C}{c}\)
\(\implies \frac {\sin 82^0}{43.2} = \frac {\sin 56^0}{AB}\)
\(\implies AB \times \sin 82^0 = 43.2 \times \sin 56^0\)
\(\therefore AB = \frac {43.2 \times \sin 56^0}{\sin 82^0}\) = 36.2cm (to 3 s.f)