Advertisements
Advertisements
प्रश्न
In the given figure. PQ = PS, P =R = 90°. RS = 20 cm and QR = 21 cm. Find the length of PQ correct to two decimal places.
Advertisements
उत्तर

In ΔSRQ, ∠R = 90°
∴ QS2 = RS2 + QR2 ....(Pythagoras Theorem)
= 202 + 212
= 440 + 441
= 841
Now,
In ΔQSP, ∠P = 90°
∴ QS2 = PQ2 + PS2
⇒ QS2 = PQ2 + PQ2 ....(Pythagoras Theorem)
⇒ QS2 = 2PQ2 ....(Given PQ = PS)
⇒ PQ2 = `"QS"^2/(2) = (841)/(2)` = 420.5
⇒ PQ = 20.50cm.
APPEARS IN
संबंधित प्रश्न
A ladder 10 m long reaches a window 8 m above the ground. Find the distance of the foot of the ladder from base of the wall.
In the given figure, ABC is a triangle in which ∠ABC < 90° and AD ⊥ BC. Prove that AC2 = AB2 + BC2 − 2BC.BD.

In the given figure, AD is a median of a triangle ABC and AM ⊥ BC. Prove that:

`"AC"^2 = "AD"^2 + "BC"."DM" + (("BC")/2)^2`
PQR is a triangle right angled at P. If PQ = 10 cm and PR = 24 cm, find QR.
Find the perimeter of the rectangle whose length is 40 cm and a diagonal is 41 cm.
In the given figure, ∆ABC is an equilateral triangle of side 3 units. Find the coordinates of the other two vertices ?

In the given figure, AB//CD, AB = 7 cm, BD = 25 cm and CD = 17 cm;
find the length of side BC.
Two poles of heights 6 m and 11 m stand vertically on a plane ground. If the distance between their feet is 12 m;
find the distance between their tips.
In triangle ABC, angle A = 90o, CA = AB and D is the point on AB produced.
Prove that DC2 - BD2 = 2AB.AD.
ABC is a triangle, right-angled at B. M is a point on BC.
Prove that: AM2 + BC2 = AC2 + BM2
Prove that in a right angle triangle, the square of the hypotenuse is equal to the sum of squares of the other two sides.
In the right-angled ∆LMN, ∠M = 90°. If l(LM) = 12 cm and l(LN) = 20 cm, find the length of seg MN.
Find the Pythagorean triplet from among the following set of numbers.
9, 40, 41
In a triangle ABC right angled at C, P and Q are points of sides CA and CB respectively, which divide these sides the ratio 2 : 1.
Prove that: 9AQ2 = 9AC2 + 4BC2
If ΔABC ~ ΔPQR, `("ar" triangle "ABC")/("ar" triangle "PQR") = 9/4` and AB = 18 cm, then the length of PQ is ______.
In figure, PQR is a right triangle right angled at Q and QS ⊥ PR. If PQ = 6 cm and PS = 4 cm, find QS, RS and QR.
Prove that the area of the equilateral triangle drawn on the hypotenuse of a right angled triangle is equal to the sum of the areas of the equilateral triangles drawn on the other two sides of the triangle.
Lengths of sides of a triangle are 3 cm, 4 cm and 5 cm. The triangle is ______.
In a right-angled triangle ABC, if angle B = 90°, BC = 3 cm and AC = 5 cm, then the length of side AB is ______.
