Page 13 - modul trigonometri_Neat

C

Example 1.1
6 cm
Look at the ABC triangle on the side.
Specify a value of 2 sin A tan C.
A B
8 cm

Alternatife Solutions

Ac side length:

2
2
= √ +
2
2
= √8 + 6
= √64 + 36 C
= √100
= 10 hypotenuse
6 cm opposite
Note the triangle from angle A looks
8 cm
like the following triangle. A B
adjacent
6
sin = = = C
ℎ 10

The side of the triangle from the
hypotenuse
angle C looks like the following 6 cm adjacent
triangle. 8 cm
A B
8 opposite
tan = = =
6

Thus:

6 8
2 sin tan = 2 × ×
10 6

2 × 48 8
= =
60 5
8
So, the value of 2 sin A tan C is
5

9