Question

Jumlah panjang dan lebar suatu persegi panjang adalah 32cm. Sedangkan luasnya adalah 240cm. Tentukan (a) panjang dan lebarnya (b) kelilingnya dan (c) panjang diagonal persegi panjang

Answer 1

A. p+l = 32 cm  maka p = 32 - l
   L  = 240 cm
   L  = p x l
   240  =  32-l x l
   240  = 32l - l²
   l²-32l+240 = 0
   (l-12)(l-20) = 0
   maka l = 12 atau l = 20
   ambil saja lebarnya = 12 cm
   maka  p  = 32-l = 32 - 12 = 20 cm
b. Keliling  = 2(p+l) = 2 x 32 = 64 cm
c. Diagonal = √p²+l²  = √20²+12²  = √400+144 = √544  = √16x34 = 4√34 cm

Answer 2

P and L : 12 and 20 cm

Perimeter : 64 cm

Diagonal = 4√34

Further explanation  

The playground is a rectangular shape. There are several properties possessed by rectangular shapes, namely:  

• 1. each angle is equal and is a right angle  

• 2. the diagonals intersect and divide each other equally  

• 3. sides facing the same length  

There are two rectangular shapes namely square and rectangle  

Square if all sides are the same length  

The formula used in rectangular is:  

• 1.Area  

Rectangle  

$\large{\boxed{\bold{Area=w\:\times\:l}}}$

w = width  

l = length  

Square  

$\large{\boxed{\bold{area=a^2}}}$

a = length of side  

• 2. perimeter  

Rectangle  

$\large{\boxed{\bold{perimeter=2\times(w+l)}}}$

w = width  

l = length  

Square  

$\large{\boxed{\bold{perimeter=4\times\:a}}}$

a = length of side  

 

P+L = 32 cm

Area = 240 cm²

Then

P = 32-L

Area = (32-L) x L

Area =32L-L²

240 = 32L-L²

-L²+32L-240=0

L²-32L+240 = 0

(L-12)(L-20)=0

L = 12 or L = 20

Then =P= 20 or 12

B)Perimeter= 2 x (P +L) = 2 x (12+20) = 64 cm

C) Diagonal

Phytagoras :

$\rm diagonal=\sqrt{20^2+12^2}\\\\diagonal=\sqrt{400+144}\\\\diagonal=\sqrt{544}=4\sqrt{34}$

Learn more  

The ratio of the perimeters  

brainly.com/question/2142493  

The coordinates of the vertices of a rectangle  

brainly.com/question/11637180  

Solve the equation for w  

brainly.com/question/128917