In △PQR, the measure of angle Q is 90
∘
. If tanP=
3
4
and PQ=1.5cm, then what is the length (in cm) of side PR?
- A2
- B2.5
- C3
- D4.8
Solution & Step-by-step Explanation
In right-angled △PQR at Q:
tanP=
Adjacent side
Opposite side
=
PQ
QR
Given that tanP=
3
4
:
PQ
QR
=
3
4
We are given PQ=1.5cm. Substituting this into the ratio:
1.5
QR
=
3
4
QR=
3
4
×1.5=4×0.5=2cm
Now, using Pythagoras theorem in △PQR:
PR
2
=PQ
2
+QR
2
PR
2
=(1.5)
2
+(2)
2
PR
2
=2.25+4=6.25
PR=
6.25
=2.5cm
Thus, the length of side PR is 2.5cm.
tanP=
Adjacent side
Opposite side
=
PQ
QR
Given that tanP=
3
4
:
PQ
QR
=
3
4
We are given PQ=1.5cm. Substituting this into the ratio:
1.5
QR
=
3
4
QR=
3
4
×1.5=4×0.5=2cm
Now, using Pythagoras theorem in △PQR:
PR
2
=PQ
2
+QR
2
PR
2
=(1.5)
2
+(2)
2
PR
2
=2.25+4=6.25
PR=
6.25
=2.5cm
Thus, the length of side PR is 2.5cm.