An oak tree is 120 feet taller than the adjacent house. if the tree is also two and a half times the height of the house, how tall is the house? choices for the height of the house 70, 80, 90

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?

Find the midpoint m of z1=(8+5i) and z2=(12+3i)

Someone me what is the area of this figure? 18m 18m 8m 16m