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8.2 Lines, angles and triangles 1 Name each triangle. Choose from scalene, isosceles, equilateral and right-angled.

a ...................... b ......................

2 The diagram shows a frame.

a Write down a line that is:

i parallel to AB ......................

ii perpendicular to AB. ......................

b What type of angle is ÐABD? ......................

c Write down a 90° angle. ......................

3 Look at these triangles.

a Name the angle where line PQ meets line PR. ......................

b One of the angles is 30°. Without using a protractor, decide which one it is. ......................

c Which angles are less than 90°? ......................

d Estimate the size of ÐYXZ. ......................

e Estimate the size of ÐPQR. ......................

f Which angle looks less than 30°? ......................

g Use a protractor to check your answers to parts c, d and e.

© Pearson Education Ltd 2019. Copying permitted for purchasing institution only. This material is not copyright free.

8.2 Lines, angles and triangles 1 Draw a rectangle ABCD where AB is 5 cm and BC is 12 cm.

Measure:

a the length of diagonal AC

..........................

b the size of each angle in triangle ABC.

..........................

2 Draw an acute angle STU.

3 Draw an obtuse angle VWX.

4 Name each of these triangles, using its correct mathematical name.

a ...................... b ......................

c ......................

5 Which of these angles is 70°? Guess and then check with your protractor. ......................

© Pearson Education Ltd 2019. Copying permitted for purchasing institution only. This material is not copyright free.

8.2 Lines, angles and triangles 1 For each triangle:

a write how many equal sides it has b write how many equal angles it has c write the name of the triangle.

A B C

2 Look at these pairs of lines. Are the lines in each pair perpendicular, parallel or neither? Mark the parallel lines with arrows and the perpendicular lines with a right-angle symbol.

a ...................... b ......................

c ...................... d ......................

3 Circle the best estimate for each of these angles.

a 90° 45° 10°

b 100° 70° 20°

© Pearson Education Ltd 2019. Copying permitted for purchasing institution only. This material is not copyright free.

8.2 Lines, angles and triangles Core 1 a isosceles b scalene

2 a i CD ii BC or AD b acute c ÐABC, ÐBCD, ÐCDA or ÐDAB

3 a ÐQPR b ÐQPR c ÐQPR, ÐPRQ, ÐXYZ and ÐYXZ

d 76° (accept answers close to this) e 110° (accept answers close to this)

f ÐXYZ g Students check their answers to parts c–e.

Depth 1 a 13 cm b 67°, 90° and 23° (accept answers close to these)

2 Students draw an acute angle labelled STU with T at the vertex

3 Students draw an obtuse angle labelled VWX with W at the vertex

4 a equilateral b right-angled isosceles c isosceles

5 ÐXYZ

Support 1 a A 2, B 0, C 3 b A 2, B 0, C 3 c A isosceles, B scalene, C equilateral

2 a parallel b neither c perpendicular d neither

3 a 10° b 70°