Chapter 4 BLM Answers

.…BLM 4–15.…

(continued)

Chapter 4 BLM Answers

.…BLM 4–15.…

(continued)

BLM 4–2 Chapter 4 Get Ready

1. a) 5 : 20 or 5 to 20 b) 9 : 27 or 9 to 27

c) 3 : 18 or 3 to 18

2. a) 1 : 4 or 1 to 4 b) 1 : 3 or 1 to 3

c) 1 : 6 or 1 to 6

3. a) 0.25, 25% b) , c)

4. a) 6 b) 21 c) 1 d) 2

5. a) b) . If students use this method, have them note that the units in the numerators must be the same and the units in the denominators must be the same, although not the same from numerator to denominator.

c) Examples:

• Converting all measures to centimetres:

• Not converting all measures to same units:

Have students note that the units in the numerators are different from those in the denominators but the same from numerator to numerator and from denominator to denominator.

6. ; x = 0.25. The student’s shadow is 0.25 m in length.

7. ; x = 100. The distance from Town A to Town C is 100 km.

BLM 4–5 Section 4.1 Extra Practice

1. a) Example using 0.5-cm grid:

b) Example using 1-cm grid:

2. Example using 0.5-cm grid:

3. a) Example using 0.5-cm grid:

b) Example using 1-cm grid:

4. Example using 0.5-cm grid:

5. Greater than 1. Example: The second image is an enlargement.

6. Example: Check that each dimension of the image is proportionally larger than the original.

BLM 4–7 Section 4.2 Extra Practice

1. a) multiply b) multiply c) divide d) multiply

2. a) 78 b) 1260 c) 34.8 d) 80 e) 86 f) 0.3

3. a) 70 cm b) 9 mm

4. a) 0.5 b) 0.06 c) 0.02 d) 0.25 e) 0.75
f) 0.8

5. 9.4. The scale factor is approximately 9.4.

6. a) 1 cm represents x km. b) 162.5

BLM 4–9 Section 4.3 Extra Practice

1. a) Corresponding angles: ÐE and ÐQ; ÐF and ÐR; ÐD and ÐP. Corresponding sides: DE and PQ; EF and QR; DF and PR.

b) Corresponding angles: ÐN and ÐG; ÐM and ÐH; ÐO and ÐF. Corresponding sides: ON and FG; NM and GH; MO and HF.

2. Yes, the triangles are similar. Look for proof of corresponding angles equal in measure or corresponding sides proportional in length. Example: Corresponding sides proportional in length: = 3; = 3;
= 3

3. a) Example:

b) Corresponding angles: ÐK and ÐX; ÐL and ÐY; ÐJ and ÐW. Corresponding sides: JK and WX; KL and XY; LJ and YW.

4. = 1.9; = 1.9; ; x = 7.6. The missing side length is 7.6.

5. = 2.5. The ramp is 2.5 m in height.

BLM 4–11 Section 4.4 Extra Practice

1. a) CDEF and RSTU are similar. Example: Corresponding angles are equal in measure:
ÐC = 115° and ÐR = 115°; ÐD = 65° and
ÐS = 65°.
Corresponding sides are proportional in length: = 1.5; = 1.5. Both conditions for similar polygons have been met.

b) MNOP and WXYZ are not similar. Example: Corresponding sides are not proportional in length: = 2.2; = 2; = 2; = 2.2. Since both corresponding angles equal in measure and corresponding sides proportional in length are necessary for similar polygons, MNOP and WXYZ are not similar.

2. = 2.1; = 2.1;
= 2.1; x = 3. The missing side
length is 3.

3. a) The scale factor is 8000. The missing lengths of the fencing are shown.

b) 1160 m