Jonatas é marceneiro e elaborou o projeto de um armário de canto de base triar Observe, na figura abaixo, um esboço desse projeto.
104
45°
ө,
Abertura
da porta
Jonatas projetou que a porta desse armário tenha um ângulo máximo de abertura equivalente a
da medida do ângulo e indicado nesse esboço.
Qual é a medida do ângulo máximo de abertura da porta desse armário?
A) 62°
B) 90°
C) 208
D) 298

Here is their argument. given the obtuse angle x, we make a quadrilateral abcd with ∠dab = x, and ∠abc = 90◦, and ad = bc. say the perpendicular bisector to dc meets the perpendicular bisector to ab at p. then pa = pb and pc = pd. so the triangles pad and pbc have equal sides and are congruent. thus ∠pad = ∠pbc. but pab is isosceles, hence ∠pab = ∠pba. subtracting, gives x = ∠pad−∠pab = ∠pbc −∠pba = 90◦. this is a preposterous conclusion – just where is the mistake in the "proof" and why does the argument break down there?

I’m confused on how to work the pie charts

Aremote-controlled boat can travel at 4 feet per second in calm water. the boat traveled 48 feet with the current, and then it traveled 16 feet against the current in the same amount of time. how fast is the current?