Question

what is the area of triangle def? round to the nearest tenth of a square unit. 10.3 square units 18.0 square units 20.0 square units 20.6 square units trigonometric area formula: area = \frac{1}{2}ab\sin(c)

Explanation:

Step1: Identify sides and included angle

a=8, b=5, C=116°

Step2: Apply area formula

Area = (1/2)85*sin(116°)

Step3: Calculate sin(116°)

sin(116°) ≈ 0.8988

Step4: Compute area

Area ≈ (1/2)400.8988 ≈ 17.976 ≈ 18.0

Answer:

B. 18.0 square units