Question

Find the area of obtuse triangle ABC when A=41 degrees, a=18cm, and b=22cm.

Answer 1

36 cm²

Explanation:

• cos A= (`sqrt(b)` + `sqrt(c)` - `sqrt(a)`)/(2bc)

⇒c ≈ 5 cm

Sabc= (1/2)bcsin A ≈ 36 cm²