Question

If the diagonal of a rectangle is double the 8.5 CM and it's perimeter is 6cm more than the 40cm then find the area of the rectangle

Answer 1

Answer:

area of rectangle is 120 cm^2

hope it helps you thanks

Step-by-step explanation:

diagonal =8.5×2=17 cm

perimeter 40+6=46 cm

length+breadth =46/2=23

let length be x and breadth 23-x

now diagonal of a rectangle makes 2 same right angle triangles

so area of 2 triangles=area of rectangle

now first we have to know the length and breadth

using pythagoras theorem

x^2+(23-x)^2=17^2

x^2+x^2+23^2-2(23x)=17^2

2x^2-46x+529=289

2x^2-46x+240=0 (÷2)

x^2-23x+120 middle term split

x^2-8x-15x+120

x-8(x-15) x=8 and 15

so length be 8 then breadth be 15,if length be 15 then breadth be 8

now area of rectangle

2(1/2 ×15×8)

120