Question

In the figure below, PQRS is a rectangle and the length of QR is twice the length of SR. Find the area(in sq. cm) of the shaded triangle.

Answer 1

l=12;b=12/2=6;
area of rectangle=l*b=12*6=72;
area of shaded region= area of rectangle-(area of big triangle and small triangle)
area of shaded region=72-(36+9)=72-45=27
so therefore the area of shaded region=27

Answer 2

Hey !!

Here is your solution...

Area of ∆PRT = 1/2 × Base × Height

◻PQRS is a rectangle.

QR = 12 cm

TS = 3 cm

Given that length of QR is twice length of SR.
QR = 2( SR )
12 = 2 ( SR )
SR = 12/2
SR = 6 cm

In ◻PQRS
QR = PS = 12cm
PS = PT + TS
12 = PT + 3
PT = 12 - 3
PT = 9 cm

Area of ∆PRT = 1/2 × PT × RS
= 1/2 × 9 × 6
= 54/2
= 27 sq. cm

HOPE IT HELPS YOU....

THANKS....
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