Answer:
7. 62.8 sq.in.
8. 21.2 sq.in.
Step-by-step explanation:
The formula of an area of a triangle:
[tex]A_\triangle=\dfrac{1}{2}ab\sin\theta[/tex]
a, b - adjacent sides
θ - included angle
=============================================
7.
a = 9in, b = 14in, θ = 85°
sin85° ≈ 0.9962
Substitute:
[tex]A_\triangle=\dfrac{1}{2}(9)(14)\sin85^o=\dfrac{1}{2}(126)(0.9962)\approx62.8 in^2[/tex]
8.
a = 12 in, b = 5 in, θ = 135°
sin135° = sin(180° - 45°) = sin45° ≈ 0.7071 used sin(180° - x) = sin(x)
Substitute:
[tex]A_\triangle=\dfrac{1}{2}(12)(5)\sin135^o=\dfrac{1}{2}(60)(0.7071)\approx21.2\ in^2[/tex]
