PSLE QRST and SVXU are identical parallelograms. WSR and UTS are identical right-angled triangles.
- Find ∠y.
- Find ∠z.
- Select the words that describe RWV in the statement:
RWV (is/is not) a straight line because the sum of angles RWS and SWV (is/is not) 180° Give your answers in this format. (Eg is, is not)
(a)
∠y
= 180° - 75°
= 105° (Interior angles)
(b)
∠USV
= ∠RST
= 105° (Parallelogram)
∠RSW
= 180° - 90° - 22°
= 68° (Angles sum of triangle)
∠z
= 360° - 105° - 105° - 22° - 68°
= 60° (Angles at a point)
(c)
∠SWV
= 180° - 28° - 60°
= 92°
Since ∠SWV is not 90°, it does not add up to 180° with ∠RWS to form a straight line. So, RWV
is not a straight line because the sum of angles RWS and SWV
is not 180°.
Answer(s): (a) 105°; (b) 68°; (c) is not, is not