import math
a_base = 3
b_left_side = 4
c_right_side = 5
perimeter = a_base + b_left_side + c_right_side
print("Perimeter = %.2f" % round(perimeter, 2))
semi_perimeter = (a_base + b_left_side + c_right_side) / 2
area_triangle1 = math.sqrt(semi_perimeter * (semi_perimeter - a_base) *
(semi_perimeter - b_left_side) *
(semi_perimeter - c_right_side))
print("Area triangle1 = %.2f" % round(area_triangle1, 2))
b_base = 4
a_right_side = 6
angle_ab = 55
area_triangle2 = (a_right_side * b_base * math.sin((math.pi / 180) * angle_ab)) / 2
print("Area triangle2 = %.2f" % round(area_triangle2, 2))
height = 5
b_base = 8
area_triangle3 = (b_base * height) / 2
print("Area triangle3 = %.2f" % area_triangle3)
'''
run:
Perimeter = 12.00
Area triangle1 = 6.00
Area triangle2 = 9.83
Area triangle3 = 20.00
'''
