Troy borrowed money from his father so that he could buy a used car. The table shows the remaining balance, b, of Troy’s loan after each payment.

Which function can be used to describe this relationship?

A b = 3910 – 225p

B b = 4135 – 225p

C b = 2785 + 225p

D b = 3685 – 225p

Obj 1 - TAKS 2004 10th [A.B1(B)] Problem #8

Engage Learning!

• Fill out the Graphic Organizer with as many examples as you can

before the next part of the lesson starts.

Can someone Explain this?

• Watch the Brain Pop and fill in the Vocabulary activity while you watch.

• When the Brain Pop is over, complete as much of the Word Find as you can before the next part of the Lesson.

What is an Angle?

An angle is a figure formed by two rays, or sides, with a common endpoint called the vertex (plural: vertices). You can name an angle several ways: by its vertex, by a point on each ray and the vertex, or by a number.

Check It Out! Example 1

Write the different ways you can name the angles in the diagram.

RTQ, T, STR, 1, 2

The set of all points between the sides of the angle is the interior of an angle. The exterior of an angle is the set of all points outside the angle.

Angle NameR, SRT, TRS, or 1

You cannot name an angle just by its vertex if the point is the vertex of more than one angle. In this case, you must use all three points to name the angle, and the middle point is always the vertex.

Find the measure of each angle. Then classify each as acute, right, or obtuse.

Example 2: Measuring and Classifying Angles

A. WXV

B. ZXW

mWXV = 30°

WXV is acute.

mZXW = |130° - 30°| = 100°

ZXW = is obtuse.

Types of Angles

Angle & Segment Addition Postulates

Test this out with a ruler and spagetti!

Spaghetti Snappingor

Segment Addition Post• Use the edge of the TAKS chart to measure

your Spaghetti in cm.• Break your Spaghetti into two pieces that are

not the same length.• Measure each of the lengths separately.• Add the lengths of those smaller pieces

together.• Do they add up the length of the original

piece?

Angle Addition Post.

If you have two pieces of pizza and someone takes one, then puts that entire piece back, do you have as much pizza as you did before?

Check It Out! Example 3

mXWZ = 121° and mXWY = 59°. Find mYWZ.

mYWZ = mXWZ – mXWY

mYWZ = 121 – 59

mYWZ = 62

Add. Post.

Substitute the given values.

Subtract.

An angle bisector is a ray that divides an angle into two congruent angles.

JK bisects LJM; thus LJK KJM.

Example 4: Finding the Measure of an Angle

KM bisects JKL, mJKM = (4x + 6)°, and mMKL = (7x – 12)°. Find mJKM.

DON’T FORGET!

• COMPLETE YOUR EXIT TICKET AND DROP IT INTO THE BASKET ON YOUR WAY OUT OF THE ROOM!