TRIANGLES
SPI: 6.4.1Identify, define or describe geometric
shapes given a visual representation or written description of its properties
TRIANGLE
• A triangle is a polygon with three sides and three angles.
The sum of the angles of a triangle is 180° because a triangle is half of a
quadrilateral.
The sum of the measures of the angles of a triangle is 180°.
• Angle 1° + angle 2° + angle 3°=180°
1°
2°
3°
If angle 1=30°, angle 2=100°, what would angle 3 equal?
50°
An acute triangle has all acute angles. (All angles are less than 90 degrees.)
A right triangle is a three sided figure with one right angle.
90°
An obtuse triangle has one obtuse angle (an angle that is more than 90°).
A scalene triangle is a three sided figure that has no angles or sides
equal.
An isosceles triangle has two sides and two angles equal.
An equilateral triangle has equal sides and equal angles.
A plane had wings that are shaped like triangles. Find the missing measure.
40 °X°
50°=x