RECTANGLE PERIMETER

 Find the perimeter of the following rectangle. (diagram not to scale)

Solution

Length=60 cm, Width = 20 cm

Perimeter = 2(length + width)

                   = 2( 60 + 20)

                   =2 x 80

                   =160cm

Hence Perimeter is 160cm

LCM

Find the LCM of 50 and 60.

Solution    

ALGEBRA - 2

If  1m  =  50; find m

     8

Solution

1m  =  50

8

¹8 x 1m  =  50 x  8     multiply by 8 on both sides

      ₁8

1m = 50 x 8

m = 400

Hence m = 400      

 

ALGEBRA - 1

If 4y = 32; find y

Solution

4y = 32

4y  =32          dividing by 4 on both sides

4       4

y = 8 

Hence y = 8     

 

CIRCLE PERIMETER - 1

Find the perimeter of the following circle

solution

P = 2 x ∏ x r

   = 2 x 22 x 560⁸⁰

             7₁

   = 2 x 22 x 80

   = 44 x 80

   = 3520m

Hence perimeter = 3520metres.    

AREA OF TRIANGLE - 2

Area of triangle is 80cm². If base is 40m, find height.

Solution

 

You can draw a simple diagram as shown below

 

 

Area =  1 x base x height

              2

 

Let height = h

80 =  1 x 40  x h

          2

80 =  1 x 40²⁰ x h,     canceling by 2

          2₁

80 =  1 x 20  x  h

 

80 = 20h

            

⁴80 =  ¹20h

₁20     ₁20

h = 4cm

 

hence height is 6cm

AREA OF TRIANGLE - 1

Find the area of the following figure

Solution

              Area =  1 x base x height

                           2

             base=15cm, height=20cm.

              Area =  1 x 15 x 20

                           2

              Area =  1 x 15 x 20¹⁰     [canceling by 2]

                          2₁

              Area =  1 x 15 x 10

            

              Area =  150

                                              Hence Area is 150 cm²