Area (ABC)?
Area (HBC)?
a=3,b=5,c=4.
149
area ABC = (a+b)*c/2 = (3+5)*4/2 = 16 cm^2
area BCH = b*c/2 = 5*4/2 = 10 cm^2
150
angolo cOa = x = 145°
angolo bOa = y = 32°
angolo cOb = x-y = 145°-32° = 113°
151
AD = h = √5^2-3^2 = 4 cm
perimetro 2p = (2x+a+h+b) = 8+3+4+5 = 20 cm
area A = (2x+a)*h/2 = 11*2 = 22 cm^2
152
area A = a(a+b)-b(a-b)-c^2
A = 7*(7+6)-6*1-2*2 = 81 cm^2