"How are we ever going to build this bridge?" asks Omkar looking out across the raging river.
"Let's start by finding the distance to the big rock on the other side." Melissa replies. Moving 100100100 meters along the river, Melissa looks back and measures the angle between Omkar and the big rock: 33^\circ33

33, degrees.
Melissa then instructs Omkar to measure the angle between Melissa and the big rock. From his vantage point, Omkar sees an angle of 98^\circ98

98, degrees between Melissa and the big rock.
What is the distance across the river from Omkar to the big rock?
Do not round during your calculations. Round your final answer to the nearest meter.

Respuesta :

Answer:

The distance across the river from Omkar to the big rock is 72 meters.

Step-by-step explanation:

Using the given information draw as triangle as shown below.

According to angle sum property, the sum of interior angles of a triangle is 180°.

In triangle ABC,

\angle A+\angle B+\angle C=180^{\circ}

98^{\circ}+33^{\circ}+\angle C=180^{\circ}

131^{\circ}+\angle C=180^{\circ}

\angle C=180^{\circ}-131^{\circ}=49^{\circ}

The measure of angle C is 49°.

Sine formula:

\frac{a}{\sin a}=\frac{b}{\sin b}=\frac{c}{\sin c}

Using sine formula in triangle ABC, we get

\frac{AC}{\sin B}=\frac{AB}{\sin C}

\frac{AC}{\sin 33^{\circ}}=\frac{100}{\sin 49^{\circ}}

AC=\frac{100}{\sin 49^{\circ}}\times \sin 33^{\circ}

AC=\frac{100}{0.7547}\cdot0.544639

AC=72.166

AC\approx 72

Therefore the distance across the river from Omkar to the big rock is 72 meters.

Answer:

72

Step-by-step explanation:

khan academy