60 likes | 182 Views
Aim: How to prove triangles are congruent using a 5 th shortcut: Hyp-Leg. Pythagorean Theorem. a. c. a 2 + b 2 = c 2. b. Do Now:. In a right triangle, the length of the hypotenuse is 20 and the length of one leg is 16. Find the length of the other leg. 20. x. 12.
E N D
Aim: How to prove triangles are congruent using a 5th shortcut: Hyp-Leg. Pythagorean Theorem a c a2 + b2 = c2 b Do Now: In a right triangle, the length of the hypotenuse is 20 and the length of one leg is 16. Find the length of the other leg. 20 x 12 x2 + 162 = 202 16 x2 + 256 = 400 x2 = 144 x = 12
Hypotenuse-Leg V.HYP-LEG DABC and DA’B’C’ are right triangles A A’ B C B’ C’ If hypotenuse AC hypotenuse A’C’, and leg BC leg B’C’ then right DABC right DA’B’C’ If the Hyp-Leg Hyp-Leg, then the right triangles are congruent
Model Problem ABC, BD AC, AB CB. Explain why ADB CDB. DABC and DCBD are right triangles – BD AC and form right angles, Triangles with right angles are right triangles. AB BC – We are told so, and both AB & BC are hypotenuses (of DABD & DBDC respectively) Hyp Hyp BD BD – Anything is equal to itself; BD is a leg for both right triangles - Reflexive Leg Leg ADB CDBbecause of Hyp - Leg Hyp - Leg
Model Problem ABD is right, CDB is right, AD CB. Explain why ADB CDB. DABD and DCBD are right triangles – Triangles with right angles are right triangles. AD CB – We are told so, and both AC & BD are hypotenuses (of DBCA & DCBD respectively) Hyp Hyp BD BD – Anything is equal to itself; BD is a leg for both right triangles - Reflexive Leg Leg ADB CDBbecause of Hyp - Leg Hyp - Leg
Model Problem PB AC, PD AE, AB AD. Explain why ABP ADP DADP and DABP are right triangles – PB AC and PD AE and form right angles, Triangles with right angles are right triangles. AB AD – We are told so, and each is a leg of their respective triangles. Leg Leg AP AP – Anything is equal to itself – Reflexive; AP is the hypotenuse of both triangles Hyp Hyp ABP ADPH-L H-L
Model Problem A D If AB BC, DC BC and AC BD, prove DBCA DCBD. E B C DABC and DCBD are right triangles – AB BC and DC BC and form right angles, Triangles with right angles are right triangles. AC BD – We are told so, and both AC & BD are hypotenuses (of DBCA & DCBD respectively) Hyp Hyp BC BC – Anything is equal to itself; BC is a leg for both right triangles - Reflexive Leg Leg DBCA DCBD because of Hyp - Leg Hyp - Leg