Question

Given the rectangle below with length 8 and width 6

Answer 1

Answer:

a) Given in attachment.

b) Quadrilateral formed is a rhombus. Because length of all the sides are equal and angle between adjacent sides is not 90°.

c) 24 unit².

Step-by-step explanation:

Let rectangle be ABCD with length 8 and width 6

And mid-points be E,F,G,H

Now, join the mid-points .

we know that angle between adjacent sides in a rectangle is 90°.

⇒ ΔFAE forms a right angle triangle with 90° at A.

By, pythagoras theorem , EF² = AF² + AE²

⇒ EF² = 3² + 4² = 25

⇒ EF = 5;

In the same way, FG = GH = HE = 5

⇒ the quadrilateral is either square or rhombus.

Now, from ΔFAE,   sin(∠AEF) = $\frac{4}{5}$

(sinФ = opposite side / hypotenuse)

⇒ ∠AEF = 53°;

In similar manner;

∠DEH = 53° . Now ∠FEH = 180 - 53 - 53 = 74° (sum of angles on a straight line is 180°)

⇒ the quadrilateral is rhombus has angle between adjacent sides is 53° and not 90°.

Now, to find the area of rhombus, join EG and FH. And name the intersection point as J.

consider ΔEJF,

it is a right angled triangle at J, and also quadrilateral AFJE forms rectangle, as diagonals intersect perpendicular in a rhombus.

⇒ FJ = 3 and EJ = 4.

⇒ area of this triangle = 1/2 × base × height

                                     = 1/2 × EJ × JF = 1/2 × 3 ×4 = 6

similarly triangles FJG, GJH, HJE.

⇒ area of rhombus = 6+6+6+6 = 24.