Answer:
- 9) 130 units;
- 10) m∠1 = 36°, m∠2 = 56°, m∠3 = 124°, m∠4 = 88°, m∠5 = 36°;
- 12) x = 8.
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All three question involve midsegments.
Properties of a midsegment:
- Midsegment is connecting midpoints of two sides;
- Midsegment is parallel to opposite side of the triangle;
- Midsegment is half the length of the parallel side.
Question 9
Perimeter is the sum of side measures.
Side measures are:
- MP = 2QR = 2*25 = 50
- NP = 2QS = 2*22 = 44
- MN = 2SR
- 5x - 34 = 2(x + 4)
- 5x - 34 = 2x + 8
- 5x - 2x = 8 + 34
- 3x = 42
- x = 14
- MN = 5*14 - 34 = 70 - 34 = 36
Perimeter of ΔMNP is:
Question 10
Corresponding angles are congruent:
Linear pair adds up to 180°:
- m∠5 = 180° - 144° = 36° and therefore m∠1 = 36°;
- m∠3 = 180° - 56° = 124°
Find m∠4 using triangle sum theorem:
- m∠4 = 180° - (36° + 56°) = 88°
Question 12
The two angles are congruent as corresponding angles:
- 9x - 23 = 6x + 1
- 9x - 6x = 1 + 23
- 3x = 24
- x = 8