state and prove Pythagoras theorem
Answers
Step-by-step explanation:
Statement: In a right angled triangle, the square of the hypotenuse is equal to the sum of the squares of the other two sides.
Given: ABC is a triangle in which ∠ABC=90∘
Construction: Draw BD⊥AC.
Proof:
In △ADB and △ABC
∠A=∠A [Common angle]
∠ADB=∠ABC [Each 90∘]
△ADB∼△ABC [A−A Criteria]
So, ABAD=ACAB
Now, AB2=AD×AC ..........(1)
Similarly,
BC2=CD×AC ..........(2)
Adding equations (1) and (2) we get,
AB2+BC2=AD×AC+CD×AC
=AC(AD+CD)
=AC×AC
∴AB2+BC2=AC2 [henceproved]
Given: ABC is a triangle in which ∠ABC=90⁰
Construction: Draw BD⊥AC.
Proof:
In △ADB and △ABC
∠A=∠A [Common angle]
∠ADB=∠ABC [Each 90⁰]
△ADB∼△ABC [A−A Criteria]
So, AD / AB = AC / AB
Now, AB² = AD×AC ..........(1)
Similarly,
BC² = CD×AC ..........(2)
Adding equations (1) and (2) we get,
AB² +BC² =AD×AC+CD×AC
=AC(AD+CD)
=AC×AC
∴AB²+BC² = AC²
Hence proved.