Step-by-step explanation:
In ΔKLM, l = 570 cm, k = 490 cm and ∠K=46°. Find all possible values of ∠L, to the nearest degree.
K
L
M
k = 490
l = 570
46°
?°
\frac{\sin A}{a}=\frac{\sin B}{b}
a
sinA
=
b
sinB
From the reference sheet (reciprocal version).
\frac{\sin L}{570}=\frac{\sin 46}{490}
570
sinL
=
490
sin46
Plug in values.
\sin L=\frac{570\sin 46}{490}\approx 0.836783
sinL=
490
570sin46
≈0.836783
Evaluate.
L=\sin^{-1}(0.836783)\approx 56.8\approx 57^{\circ}
L=sin
−1
(0.836783)≈56.8≈57
∘
Inverse sine and round.
\text{Quadrant II: } 180-57=123^{\circ}
Quadrant II: 180−57=123
∘
Sine is positive in quadrants 1 and 2.
\text{Check for possibility:}
Check for possibility:
No triangle's angles may add to more than 180.
46+57=103
46+57=103
∘
←Possible
Less than 180.
46+123=169}
46+123=169
∘
←Possible
Less than 180.
Answer: 57
and 123
(rounded)