Question

Can you help me with #20? In details I am so lost

Answer 1

Area of a triangle = 1/2 basexheight
To find the h you use Pythagoras theory
4^2+ h^2= 8^2
16+h^2=64
H^2=48
H=6.93

1/2x8x6.93=27.72

Area of a circle is pir^2
3.14*2^2= 12.56( since it’s half a circle divide by two)
12.56/2= 6.28 (now subtract this from the area of the triangle)
27.72-6.28= 21.44
The answer is 21.44

Answer 2

Area of an equilateral triangle is $\frac{ s^{2} \sqrt{3} }{4}$, where s is length of a side; we have s = 2 + 4 + 2 = 8 mm; then area is $16 \sqrt{3} ;$;
Area of a semi-circle = (1/2)π$r^{2}$, where r is the radius of circle; r = 4/2 = 2 mm; then area is 2π;
The shaded area is $16 \sqrt{3} - 2π = 2( [tex]8 \sqrt{3}$ - π );