Question

in the ad joining figure,in triangle PQR,PR=8cm,QR=4cm,and PL=5cm.find
A.area of triangle PQR
B. The length of QM​

Answer 1

Answer:

find the value of LR

PL²+LR²=PR²

5² +LR² =8²

LR =√64-25

LR. =√39

LR=6.24cm

now,

LQ=6.24-4=2.24cm

in triangle PLQ

PL²+LQ²=PQ²

5²+2.24²=PQ²

25+5.01=PQ²

PQ=5.47cm

Area of triangle( PLR)=1/2×B×H

=1/2×6.24×5

=15.6 cm²

Area of triangle(PLQ)=1/2×B×H

=1/2×2.24×5

=5.6 cm²

area of ∆PQR=15.6-5.6

=10 cm²

1/2×8×QM=10

QM=10/4

QM=2.5 cm

Answer 2

Answer:

(i) 10 cm^2

(ii) 2.5 cm

Step-by-step explanation:

Given,

PR=8cm, QR=4cm and PL=5cm

(i)

Base = QR = 4 cm

Height = PL = 5 cm

Area of ΔPQR = (1/2) * base * height

                       = 1/2 * 4 * 5

                       = 10 cm²

(ii)

Base = PR = 8 cm

Height = QM = ?

Area of ΔPQR = 1/2 * base * height

=> 10 = (1/2) * 8 * QM

=> 20 = 8 * QM

=> QM = 2.5 cm

Hope it helps!