The area of the square ABCD is 16 cm². Its area is divided into 4 equal squares. Line EH passes through the center of the large square.
Angle AHG is 90°. Find the area of the yelow-bordered region.
On my PC the picture is clear enough. What part do you not understand? Let me know.
um the picture is blocked on my browser. You might have to screenshot it.
Yes thanks, we can see the pic now.
I would tackle this question by using coordinate geometry.
A((0,0)
B(0,4)
C((4,4)
D(4,0)
centre(2,2)
work out H (intersection of 2 lines)
then work out E
then look at areas.
AD = 4 cm
AG = 2 cm
Area of square ABCD = AD² = 16 cm²
AH = 1.789
Angle ABG = 26.565°
GH = sqrt(AG² - AH²) = 0.894
Area ABHFD = (AB * AG) - [(AH * GH) /2] = 7.2 cm²
BG = sqrt( 4² + 2² ) = 4.472
BH = BG - GH = 3.578
HL = cos(26.565°) * 3.578 = 3.2
BL = sqrt[(BH)² - (HL)²] = 1.6
Area of Δ BHL = (HL * BL) /2 = 2.56 cm²
Angle ABG = BHE = 45°
Angle EHL = ∠BHE - ∠BHL = 18.435°
EL = tan( 18.435°) * 3.2 = 1.067
Area of Δ EHL = ( HL * EL) /2 = 1.707 cm²
Area CFHE = 16 - ( 7.2 + 2.56 + 1.707 ) = 4.533 cm²