In a right-angled triangle show that the hypotenuse is the longest side.
Answer:
- Let PQR be a right-angled triangle such that ∠Q=90∘.
- As the sum of angles of a triangle is 180∘.
Now, in △PQR, we have ∠P+∠Q+∠R=180∘⟹∠P+90∘+∠R=180∘[As,∠Q=90∘]⟹∠P+∠R=180∘−90∘⟹∠P+∠R=90∘ As the measure of ∠Q is equal to the sum of measures of ∠P and ∠R, we have ∠Q>∠P⟹PR>QR… (1) [Side opposite to greater angle is greater.] Also, ∠Q>∠R⟹PR>PQ… (2) [Side opposite to greater angle is greater.] - By equation (1) and (2) , we have PR>QR and PR>PQ As PR is greater than both the sides, PR is longest side.