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° - 79°
= 101° (Interior angles)
(b)
∠LJM
= ∠HJK
= 101° (Parallelogram)
∠HJN
= 180° - 90° - 25°
= 65° (Angles sum of triangle)
∠r
= 360° - 101° - 101° - 25° - 65°
= 68° (Angles at a point)
(c)
∠JNM
= 180° - 25° - 68°
= 87°
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) 101°; (b) 65°; (c) is not, is not