PSLE GHJK and JMPL are identical parallelograms. NJH and LKJ are identical right-angled triangles.
- Find ∠q.
- Find ∠r.
- Select the words that describe HNM in the statement:
HNM (is/is not) a straight line because the sum of angles HNJ and JNM (is/is not) 180° Give your answers in this format. (Eg is, is not)
(a)
∠q
= 180° - 76°
= 104° (Interior angles)
(b)
∠LJM
= ∠HJK
= 104° (Parallelogram)
∠HJN
= 180° - 90° - 24°
= 66° (Angles sum of triangle)
∠r
= 360° - 104° - 104° - 24° - 66°
= 62° (Angles at a point)
(c)
∠JNM
= 180° - 30° - 62°
= 88°
Since ∠JNM is not 90°, it does not add up to 180° with ∠HNJ to form a straight line. So, HNM
is not a straight line because the sum of angles HNJ and JNM
is not 180°.
Answer(s): (a) 104°; (b) 66°; (c) is not, is not