PSLEThe figure is made up of two rectangles, JKRP and PQMN, and two right-angled isosceles triangles, KLR and MLQ. KJ = 14 cm, MN = 8 cm and KR =
s cm. JPN and LRQP are straight lines.
- Find the length of JN in terms of s. Give your answer in the simplest form.
- Find the total area of the figure when s = 19.
(a)
Length RQ
= 14 - 8
= 6 cm
Length LR =
s cm (Isosceles triangle)
Length QM
= Length CG
= (
s + 6) cm (Isosceles triangle)
Length JN
=
s +
s + 6
= (2
s + 6) cm
(b)
Area of Rectangle JKPR
= 19 x 14
= 266 cm
2 Length PN
=
s + 6
= 19 + 6
= 25 cm
Area of Rectangle MNPQ
= 25 x 8
= 200 cm
2 Area of Triangle KLR
=
12 x 19 x 19
= 180.5 cm
2 Area of Triangle LMQ
=
12 x 25 x 25
= 312.5 cm
2 Total area of the figure
= 266 + 200 + 180.5 + 312.5
= 959 cm
2 Answer(s): (a) (2
s + 6) cm; b) 959 cm
2