JAMB - Mathematics (1978 - No. 25)
A triangle has angles 30o, 15o and 135o. The side opposite to the angle 30o is length 6cm. The side opposite to the angle 135o is equal to
12cm
6cm
6\(\sqrt{2}\)cm
12\(\sqrt{2}\)cm
Giải thích
\(\frac{6}{\sin 30}\) = \(\frac{x}{\sin 135}\)
\(\frac{6}{\sin 30}\) = \(\frac{x}{\sin 45}\)
x = \(\frac{6 \times \sin 45}{\sin 30}\)
= \(6 \sqrt{2}\)cm