Advertisements
Advertisements
प्रश्न
In the given figure, PQ = `"RS"/(3)` = 8cm, 3ST = 4QT = 48cm.
SHow that ∠RTP = 90°.
Advertisements
उत्तर

PQ = `"RS"/(3)` = 8cm
⇒ PQ = 8cm and RS = 3 x 8 = 24cm
3ST = 4QT = 48cm
⇒ ST = `(48)/(3) = 16"cm" and "QT" = (48)/(4)` = 12cm
In ΔPTQ,
PT2 = PQ2 + QT2
= 82 + 122
= 64 + 144
= 208
In ΔRTS,
RT2 = RS2 + ST2
= 242 + 162
= 576 + 256
= 832
Now, PT2 + RT2
= 208 + 832
= 1040 .....(i)
Draw PU ⊥ RS and Join PR.
PU = SQ
= ST + TQ
= 16 + 12
= 28cm
RU = RS - US
= RS - PQ
= 24 - 8
= 16cm
In ΔRUP,
PR2 = RU2 + PU2
= 162 + 282
= 256 + 784
= 1040 ....(ii)
From (i) and (ii), we get
PT2 + RT2 = PR2
Thus, ∠RTP = 90°.
APPEARS IN
संबंधित प्रश्न
Sides of triangle are given below. Determine it is a right triangle or not? In case of a right triangle, write the length of its hypotenuse. 13 cm, 12 cm, 5 cm
PQR is a triangle right angled at P and M is a point on QR such that PM ⊥ QR. Show that PM2 = QM . MR
ABC is an isosceles triangle right angled at C. Prove that AB2 = 2AC2
A guy wire attached to a vertical pole of height 18 m is 24 m long and has a stake attached to the other end. How far from the base of the pole should the stake be driven so that the wire will be taut?
Two poles of heights 6 m and 11 m stand on a plane ground. If the distance between the feet of the poles is 12 m, find the distance between their tops.
D and E are points on the sides CA and CB respectively of a triangle ABC right angled at C. Prove that AE2 + BD2 = AB2 + DE2
In the given figure, ABC is a triangle in which ∠ABC < 90° and AD ⊥ BC. Prove that AC2 = AB2 + BC2 − 2BC.BD.

Identify, with reason, if the following is a Pythagorean triplet.
(4, 9, 12)
The given figure shows a quadrilateral ABCD in which AD = 13 cm, DC = 12 cm, BC = 3 cm and ∠ABD = ∠BCD = 90o. Calculate the length of AB.
In the following figure, AD is perpendicular to BC and D divides BC in the ratio 1: 3.
Prove that : 2AC2 = 2AB2 + BC2
Calculate the area of a right-angled triangle whose hypotenuse is 65cm and one side is 16cm.
A ladder 15m long reaches a window which is 9m above the ground on one side of a street. Keeping its foot at the same point, the ladder is turned to other side of the street to reach a window 12m high. Find the width of the street.
Each side of rhombus is 10cm. If one of its diagonals is 16cm, find the length of the other diagonals.
The perpendicular PS on the base QR of a ∆PQR intersects QR at S, such that QS = 3 SR. Prove that 2PQ2 = 2PR2 + QR2
If ‘l‘ and ‘m’ are the legs and ‘n’ is the hypotenuse of a right angled triangle then, l2 = ________
Find the unknown side in the following triangles
If length of sides of a triangle are a, b, c and a2 + b2 = c2, then which type of triangle it is?
In the adjoining figure, a tangent is drawn to a circle of radius 4 cm and centre C, at the point S. Find the length of the tangent ST, if CT = 10 cm.

Lengths of sides of a triangle are 3 cm, 4 cm and 5 cm. The triangle is ______.
Two poles of 10 m and 15 m stand upright on a plane ground. If the distance between the tops is 13 m, find the distance between their feet.
