Revisit
Given that in APOR, POR = 90°, SPQ= 4 SPR PL-3, LQ-1, PM - 2, MR-3. Let A denote
area of quadrilateral MNSR, find
75
XA
2
P
2.
M M
3
L
1
\N
3
Qt
R
S
Answers
Given :- in ∆POR, ∠POR = 90°, ∠SPQ = ∠SPR , PL = 3, LQ = 1, PM = 2, MR = 3.
To Find :- (75/2) A , where A is area of quadrilateral MNSR ?
Solution :-
In right ∆PQR,
→ QR = √[PR² - PQ²] { By pythagoras theorem. }
→ QR = √[5² - 4²] = 3 .
now,
→ Area ∆PLM / Area ∆PQR = (1/2) * 3 * 2 * sin QPR / (1/2) * 4 * 5 * sin QPR = (3*2)/(4*5) = (3/10) --------- Eqn.(1)
similarly,
→ Area PLN / Area PNM = (3/2) { since PN is angle bisector .}
→ Area PNM / Area PLM = (2/5)
→ Area PNM = (2/5) Area PLM
using Eqn.(1),
→ Area PNM = (2/5) * (3/10) * (Area PQR) = (3/25) Area PQR ------- Eqn.(2)
now,
→ PQ / PR = QS / SR { By angle bisector theorem.}
→ (4/5) = QS / SR
→ QS = (4/5) SR
→ QS = (4/9) QR
→ QS = (4/9) * 3
→ QS = (4/3) unit.
then,
→ Area ∆PQS = (1/2) * Base * Height = (1/2) * (4/3) * 4 = (8/3) cm² --------- Eqn.(3)
therefore,
→ Area ⌷ MNSR = Area ∆PQR - Area ∆PQS - Area PNM
putting values from Eqn.(2) and Eqn.(3) ,
→ Area ⌷ MNSR = (1/2) * Base * Height - (8/3) - (3/25) Area PQR
→ Area ⌷ MNSR = (1/2) * 4 * 3 - (8/3) - (3/25) * {(1/2) * 4 * 3}
→ Area ⌷ MNSR = 6 - (8/3) - (3/25) * 6
→ Area ⌷ MNSR = 6 - (8/3) - (18/25)
→ Area ⌷ MNSR = (450 - 200 - 54)/75
→ Area ⌷ MNSR = (196/75) unit² = A .
hence,
→ (75/2) A = (75/2) * (196/75) = 98 unit² (Ans.)
{ Excellent Question. }
Learn more :-
in triangle ABC seg DE parallel side BC. If 2 area of triangle ADE = area of quadrilateral DBCE find AB : AD show that B...
https://brainly.in/question/15942930
2) In ∆ABC seg MN || side AC, seg MN divides ∆ABC into two parts of equal area. Determine the value of AM / AB
https://brainly.in/question/37634605