Property 2: In a right triangle, two acute angles are complementary.
Property 3: In a right triangle, the median line on the hypotenuse is equal to half of the hypotenuse.
Property 4: The product of two right angles of a right triangle is equal to the product of the hypotenuse and the height of the hypotenuse.
Property 5: As shown in the figure, in Rt△ABC, ∠ BAC = 90, and AD is the height on the hypotenuse BC, then the projective theorem is as follows:
( 1)(AD)×2=BD DC
(2) (AB) × 2 = BD BC, a diagram of projective theorem.
(3)(AC)×2=CD BC. Equal product formula
(4)ABXAC=ADXBC (usable area certificate)
(5) The radius of the circumscribed circle of the right triangle R= 1/2BC,
(6) The radius of the inscribed circle of the right triangle r= 1/2(AB+AC-BC) (formula1); R=AB*AC/(AB+BC+CA) (Formula 2)