Question

Find the area of the triangle with A = 60°, b = 11 feet, and c= 8 feet. Round to the nearest tenth.

Answer 1

38.1 sq. ft

Explanation:

angle A = 60 deg.

length a = unknown

b = 11 feet

c = 8 feet

angle B must be larger than angle C

try cos A = 8/11 ? no since cos A = 0.5 so this is not a 30-60-90 triangle

Area of triangle = (1/2)* base * height

height = ...

imagine... 8 is hypotenuse and then adjacent leg = 8*cos 60

then height = 8 * sin 60 = 8 * (root(3)/2) = 4*root(3)

Area of triangle A = (1/2)*11 feet * 4*root(3)

A =22*root(3) sq. ft. = 38.105 sq. ft = 38.1 sq. ft