Step-by-step explanation:
Given,
the bigger triangle (∆GFH), <HGF = 90° and <GFH = 60° and GF = 4
In the 30-60-90 triangle, FH = 4×2 = 8
or you can find it like this,
cos60 = 4/FH
FH = 4/cos60 = 8
Now, I is the midpoint of FH, so, FI = 8/2 = 4
now for ∆FGI,
<GFI = 60°, GF = 4, FI = 4, it's a equilateral triangle, so we can say GI = 4
Now we need to find the height of ∆FGI, for that,
area of ∆FGI = (√3/4)×4² = 4√3 = 6.92820323..
So height (GJ) = 2×area/side = 2×4√3/4 = 2√3 = 3.46410162.. [height of ∆GFI (Because altitude is perpendicular distance from a point) = GJ, given]
now, in ∆GJI, GJ = 2√3, GI = 4 and <GJI = 90° (since itsy altitude, the angle will be a right angle, i.e. 90°)
So, JI = √{4²-(2√3)²} = 2
Area = 2×2√3/2 = 2√3 = 3.46410162.. = 3.46 (rounded to the nearest hundredth)
