a) Find the perimeter of the shaded region.
b) Find the area of the shaded region.
Solution
a)
The perimeter of square ABCD is 84 cm.
1 side of square ABCD ----- 84 cm divided by 4 = 21 cm
Radius of the 6 quadrants ----- 21 cm divided by 3 = 7 cm
The shaded area is made up of 6 quadrants -----
6 x ¼ x 2 x 22/7 x 7 cm = 66 cm (Answer)
b) Redrawing the figure….
Area of 1 quadrant -----
¼ x 22/7 x 7 cm x 7 cm = 38.5 square cm
Area of 1 small partially shaded square ----
Area of 1 small square – Area of 1 quadrant ----- (7 cm x 7 cm) – 38.5 square cm = 10.5 square cm
Area of 2 such small partially shaded squares -----
10.5 square cm x 2 = 21 square cm
Area of 3 small shaded squares -----
(3 x 7 x 7) square cm = 147 square cm
Total shaded area ------
(21 + 147) square cm = 168 square cm (Answer)
Dear Mr Song
ReplyDeleteI noticed that the answers for these two questions in the cbox are different
Both these questions looked similar at first glance. Could you help to clarify the reason? 10 % more and 10% lighter? Quite confusing for P6 students.
teq: A has 10% more than B.B has 10% more than C .what is the diffrence between A and C ? a) 20% b)21% C) 30% d)31%
Excel to teq: Percentage Q, answer is (b).
Confused: Hi Mr Song, pls help me.Azizah is 10 % lighter than Bala. Bala is 10 % lighter than Caili.How many percent is Azizah lighter than Caili ? TQ.
Excel: To confused :- That Q has now become a Short Q rather than Sect C Q in most schools. Answer is 19%.
C ----- 100%
ReplyDeleteB 10% more ----- 100% + 10% = 110%
A 10% more than B ----- 110% + 11% = 121%
C more than A ----- 121% - 100% = 21%
Caili ----- 100%
Bala 10% lighter ---- 100% - 10% = 90%
Azizah 10% lighter than Bala ----- 90% - 9% = 81%
Azizah lighter than Cailing ----- 100% - 81% = 19%
Dear Mr Song
ReplyDeleteThank you for your advice.