Trigonometry
Objective: Use trigonometry functions to find the area of triangles.
In ΔPQR, PQ=12, PR=3, and m< P=78. Find the area of ΔPQR, to the nearest tenth of a square unit.

Respuesta :

The area of the triangle PQR is 17.6 square units.

Explanation:

Given that the sides of the triangle are PQ = 12 and PR = 3 and [tex]m\angle P = 78^{\circ}[/tex]

We need to determine the area of the triangle PQR

Area of the triangle:

The area of the triangle can be determined using the formula,

[tex]\text {Area}=\frac{1}{2} qr \sin P[/tex]

Substituting the values, we get,

[tex]\text {Area}=\frac{1}{2}(12)(3) \sin 78[/tex]

Simplifying, we have,

[tex]\text {Area}=\frac{1}{2}(36)(0.98)[/tex]

Multiplying the terms, we have,

[tex]\text {Area}=\frac{35.28}{2}[/tex]

Dividing, we get,

[tex]\text {Area}=17.64[/tex]

Rounding off to the nearest tenth, we have,

[tex]Area=17.6[/tex]

Thus, the area of the triangle PQR is 17.6 square units.

Answer:

17.6 units²

Step-by-step explanation:

Area = ½ × PQ × PR × sin(P)

= ½ × 12 × 3 × sin(78)

= 17.6066568132