Education english 1 ppt

CHAPTER 4 • LearningExpress Skill Builders 94

There are 230 kids total because 92 is 40% of 230.

You can check your answer: .4  230  92.

GEOMETRY

1. c.Notice that this figure contains similar triangles.

Similar triangles are in proportion. Because

AB:BD  2:3, then we know that the triangles are

in a 2:5 ratio.

This means that the bases of these 2 triangles will

also be in a 2:5 ratio.

2. b. A pentagon has five sides. If a pentagon is reg￾ular, that means that all five sides are equal. To find

the perimeter, we just add up the distance around

the pentagon.

2525252525  125 mm.

3. a. First, notice the triangle in the middle of the

rectangle. All triangles have 180°, so we know that

the 3rd angle is 50°. (95°  35°  50°  180°)

Next, notice how this question is similar to a Par￾allel Lines question:

Angle p and 50° are alternate interior angles, and

are thus equal: p  50°.

4. b. The slope is calculated by using the formula

m  Δ

Δ

x

y

, where m is the slope of the line.

We will use the points (3, 5) and (8, 10) in the

slope formula:

m  Δy 

y2

Δ

–

x

y1

 x2 – x1

 8

1

–

0

(

–

–

5 3)



1

8

0



–

3

5

 1

5

1

5. a. A reflection is like a mirror image. If we are

reflecting the figure across the y-axis, then we are

making a mirror image of it across the vertical axis.

Choice a meets this description.

95o 50o

35o

A p

C D

B

SBGeo_1 SBGeo_2 SBGeo_3

SBGeo_4 SBGeo_5

SBGeo_6

SBGeo_7 SBGeo_8

SBGeo_9

SBGeo_10

5

5

5

5

5

SBGeo_14

SBGeo_15

SBGeo_17 SBGeo_18

SBGeo_19

SBGeo_16

A

B C

D E

2 2

5

3

SBGeo_20

–BASIC SKILLS FOR COLLEGE–