Shortcut Trick
By observing the given coordinates, we can mentally calculate the differences to find side lengths.
For ΔPQR: Horizontal distance PQ = 4 − 1 = 3, Vertical distance PR = 5 − 1 = 4. The hypotenuse QR = √(32 + 42) = 5.
For ΔSTU: Horizontal distance ST = 9 − 6 = 3, Vertical distance SU = 6 − 2 = 4. The hypotenuse TU = √(32 + 42) = 5.
Since all three corresponding sides of both triangles measure 3, 4, and 5, they are identical in length.
∴ The correct answer is Yes, by SSS.
Alternate Method
Given:
Vertices of ΔPQR: P(1, 1), Q(4, 1), and R(1, 5)
Vertices of ΔSTU: S(6, 2), T(9, 2), and U(6, 6)
Formula Used:
Distance Formula = √[(x2 − x1)2 + (y2 − y1)2]
P(1, 1)
Q(4, 1)
R(1, 5)
3
4
5
S(6, 2)
T(9, 2)
U(6, 6)
3
4
5
Calculations:
⇒ Let us calculate the lengths of the sides of ΔPQR:
⇒ PQ = √[(4 − 1)2 + (1 − 1)2] = √[32 + 0] = 3 units
⇒ PR = √[(1 − 1)2 + (5 − 1)2] = √[0 + 42] = 4 units
⇒ QR = √[(1 − 4)2 + (5 − 1)2] = √[(−3)2 + 42] = √[9 + 16] = √25 = 5 units
⇒ Now, let us calculate the lengths of the sides of ΔSTU:
⇒ ST = √[(9 − 6)2 + (2 − 2)2] = √[32 + 0] = 3 units
⇒ SU = √[(6 − 6)2 + (6 − 2)2] = √[0 + 42] = 4 units
⇒ TU = √[(6 − 9)2 + (6 − 2)2] = √[(−3)2 + 42] = √[9 + 16] = √25 = 5 units
⇒ By comparing both triangles, we get: PQ = ST = 3, PR = SU = 4, and QR = TU = 5.
⇒ Since all three corresponding sides are exactly equal, the two triangles are congruent by the SSS criterion.
∴ The correct answer is Yes, by SSS.
Additional Information
SSS (Side-Side-Side) Congruence
If all three sides of one triangle are equal to the corresponding three sides of another triangle, then the two triangles are perfectly congruent.
SAS (Side-Angle-Side) Congruence
If any two sides and the included angle between them of one triangle are equal to the corresponding sides and included angle of another triangle, they are congruent.
Distance Formula in Coordinate Geometry
The linear distance 'd' between two geometric points (x1, y1) and (x2, y2) is mathematically evaluated by d = √[(x2 − x1)2 + (y2 − y1)2].