PSLEThe figure is made up of two rectangles, MNUS and STQR, and two right-angled isosceles triangles, NPU and QPT. NM = 11 cm, QR = 6 cm and NU =
v cm. MSR and PUTS are straight lines.
- Find the length of MR in terms of v. Give your answer in the simplest form.
- Find the total area of the figure when v = 20.
(a)
Length UT
= 11 - 6
= 5 cm
Length PU =
v cm (Isosceles triangle)
Length TQ
= Length CG
= (
v + 5) cm (Isosceles triangle)
Length MR
=
v +
v + 5
= (2
v + 5) cm
(b)
Area of Rectangle MNSU
= 20 x 11
= 220 cm
2 Length SR
=
v + 5
= 20 + 5
= 25 cm
Area of Rectangle QRST
= 25 x 6
= 150 cm
2 Area of Triangle NPU
=
12 x 20 x 20
= 200 cm
2 Area of Triangle PQT
=
12 x 25 x 25
= 312.5 cm
2 Total area of the figure
= 220 + 150 + 200 + 312.5
= 882.5 cm
2 Answer(s): (a) (2
v + 5) cm; b) 882.5 cm
2