Let's talk about angles too

Meet the right triangle. Well, no there is no wrong triangle. What I mean is this triangle has a right angle.

If the right triangle were lost how could you write a missing Person (or triangle) report?

Lost: my pet right triangle. You will recognize him by these attributes.

• three sides ( like all triangles)

• 180 degrees in all when every angle is added together (like all triangles)

• one right angle

• two acute angles ( That right angle takes up half the available angle degrees.)

• he calls his sides legs

• the leg opposite the right angle is call the hypotenuse (or side c)

• a² + b²  = c^{2  the Pythagorean Theorem and can be used to find the third leg.}

^{There are some fakes out there. Can you spot them?}

^{Click on the description when you think you've found your pet right triangle. Click on the box under it for the reason that you are wrong or right.}

^{Hey we found him!  He has  three sides they are 6 inches, 6 inches and six inches. He has three angles: 60◦, 60◦,and 60◦.} 

^{Man, we've got your pet. He claims to have three legs. One leg is 5, the other is 12, and the hypotenuse is 13.}

^{No, give me the reward. There is a reward isn't there? Your three legged pet has a right angle and a 30 degree angle and a 70 degree angle.}

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Angles

"Ya, I know all about angles! Right, obtuse, acute ( those cute little angles)."

"Ok, pal, how did you do on problem 33? Can you find all the angles  in this picture?"

Help is on the way. First some vocabulary:

• Complementary angles add up to 90 degrees, make a right angle
• Supplementary angles add up to 180 degrees, make a straight line
• Vertical angles both have the same value.
•          Make a vertical angle example now. Cross your arms at the wrist. Above your wrist is a vertical angle to below your wrist.
•         The opening next to your right thumb is a vertical angle to the opening next to your left thumb.
• Alternate exterior angles are angles located outside a set of parallel lines and on opposite sides of the line that divides it.
•  Alternate exterior angles are congruent (the same)

Ya, I know. We are getting to angle ABC but the only hint they gave was the 110 so we needed to start there.  Alternate exterior angles gets us to the answer. the 110 degrees is the same as the angle at B. The angle on the other side of the line is 70 degrees because it is supplementary ( makes a straight 180 degree angle).

Study these definition and click here for a multiple choice. Try to avoid fly away answers.

1. If angle ABC is complementary to  ABD they both add up to...

Remember try to get it first try to avoid this:

  a. 360

   b. 90

 c. 180

d. 45

      2. If angle XYZ is 20 degrees and is a vertical angle to WYM,  What is angle WYM?

        a.  70 to form a complementary angle

        b. 160

        c. 20

        d. you can't tell

         3. Two angles that make a straight line are..

          a. supplementary

           b. complementary

           c. alternate exterior

           d. alternate interior