In triangle ABC, side AB has a length of 8 cm and side BC has a length of 5 cm. If the triangle has an area of 10 square centimeters, what is the measure of the angle between sides AB and BC?

135°
150°
120°
45°
30°
60°

Thank you!

Respuesta :

Recall the following formula:

Given a triangle with side lengths a, b, and c. Let the measure of the angle between sides of length a and c be B.

Then, the area of the triangle is given by :

                                 [tex]Area= \frac{1}{2}\cdot a\cdot c \cdot \sin B[/tex].

 In our example we have: Area=10 square cm, a=8 cm, c=5 cm, and we want to find the measure of the angle between the 2 sides a and c.

Substituting in the formula we have:

[tex]10= \frac{1}{2}\cdot 8\cdot 5 \cdot \sin B [/tex]

Thus, [tex]10=20 \sin B[/tex], which means [tex]\sin B = \frac{1}{2} [/tex].

[tex] \frac{1}{2} [/tex] is the sine of [tex]30^{\circ}[/tex], but also [tex]150^{\circ}[/tex].


Answer: both 30, and 150 degrees are possible

Otras preguntas