McGraw Hill Glencoe Geometry, 2012
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McGraw Hill Glencoe Geometry, 2012 View details
8. Triangles and Coordinate Proof
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Exercise 3 Page 306

Notice that the triangle is isosceles.

T(2a,0)

Practice makes perfect

We are given the following triangle on a coordinate plane.

Since T is on the x-axis, its y-coordinate must be 0. Now, recall the classification of triangles.

Classification of Triangles
Scalene Triangle A scalene triangle is a triangle in which all three sides have different lengths.
Isosceles Triangle An isosceles triangle is a triangle that has two congruent sides and two base angles with the same measure.
Equilateral Triangle An equilateral triangle is a triangle in which all the sides are congruent.
Acute Triangle An acute triangle is a triangle where all angles are less than 90^(∘) or π2.
Obtuse Triangle An obtuse triangle is a triangle with exactly one an angle whose measure is greater than 90^(∘) or π2.
Right Triangle A right triangle is a specific type of triangle that contains one angle of 90^(∘).

Notice that RS≅ TS. This implies that △ RST has two congruent sides. Therefore, it is an isosceles triangle. As we can see in the diagram, O(0,0) is the midpoint of the base RT. Therefore, the x-coordinate of T is the same distance from O as R is.

In conclusion, the coordinates of T are ( 2a, 0).