**Kinds of Triangles **

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A scalene triangle is a triangle that has three unequal sides,- No two sides are equal
- No two angles are equal
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An isosceles triangle is a triangle that has two sides of equal length.- two sides (legs) are equal
- the third side is the base
- two angles (base angles) are equal
- the third angle is the vertex
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An equilateral triangle is a triangle in which all three sides are equal.- All three sides are equal
- All three angles are equal
- Each angle =60°
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An acute triangle is a triangle with all three angles acute (less than 90°).- all angles are less than 90°
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A right triangle or right-angled triangle is a triangle in which one angle is a right angle.- one angle is a right angle (equals 90°)
- side opposite the right angle is the hypotenuse
- other two sides are the legs
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An obtuse triangle is a triangle in which one of the angles is an obtuse angle.- one angle is obtuse (greater than 90°, but less than 180°)
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**Kinds of Triangles Review Problems:**

- 1) In triangle ABC, if CA = CB and the measure of angle A is 50 degrees, find the measure of angle B.

- 2) In triangle ABC AB = BC. If AB = 5x and BC = 2x + 18, find AB and BC.

- 3) In isosceles triangle ABC, AB = BC. If AB = 5x + 10, BC = 3x + 40, and AC = 2x +30, find the length of each side of the triangle.

- 4) In triangle ABC, AB = BC. If the measure of angle A = 7x and the measure of angle C = 2x + 50, find the measure of angle A and angle C

- 5) In triangle EFG, EF = FG. If the measure of angle E = 4x + 50, the measure of angle F = 2x + 60, and the measure of angle G = 14x + 30, find angles E, F, and G.

- 6) Could the following be sides of a triangle: 16, 18, and 37? Why or why not?

- 7) Could the following be sides of a triangle: 56, 59, and 115? Why or why not?

**See also: **