a, b, c - side lengths (a ≤ b ≤ c)
If
, then is Obtuse triangle.
If
, then is Right triangle.
If
, then Acute triangle.

Check to see if the sum of the first two sides is greater than the third.

, therefore is Scalene triangle.

It's Obtuse triangle.
<span>●(a + b)^2 = (a +b) (a +b)
(a + b) (a + b) = a*a + a*b + b*a+ b*b = a^2 + 2ab + b^2
●(a – b)^2 (a - b) (a -b)
(a - b) (a -b) = a*a + -ab - ba + b*b = a^2 - 2ab + b^2
●(a - b)(a + b). =
= (a - b) (a + b) = a*a + ab - ba - b*b = a^2 - b^2
</span>
PLEASE HELP! In a word processing document or on a separate piece of paper, use the guide to construct a two column proof proving that triangle RST is congruent to triangle RSQ given that RS ⊥ ST, RS ⊥ SQ, and ∠STR ≅ ∠SQR. Submit the entire proof to your instructor.
Given:
RS ⊥ ST
RS ⊥ SQ
∠STR ≅ ∠SQR
Prove:
△RST ≅ △RSQ