Figure 2 shows the plan view of a frame for a flat roof
The slope of the frame consists of triangle ABD joined to triangle BCD
Given that
BD = x cm
CD = (1+x) m
BC = 5m
angle BCD = θ°
a) show that cosθ° = (13+x)/(5+5x)

Given also that x = 2√3
x = 2√3
angle BAC = 30°
ADC is a straight line
b) find the area of the triangle ABC, giving your answer, in m^2, to one decimal place