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Raavi Tiwari
@raavi-tiwari
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Joined: May 7, 2021
Last seen: Jun 14, 2021
Topics: 0 / Replies: 2064
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Answer to: In Figure, O is a point in the interior of a triangle. ABC, OD ⊥ BC, OE ⊥ AC and OF ⊥ AB.

Given, in ΔABC, O is a point in the interior of a triangle. And OD ⊥ BC, OE ⊥ AC and OF ⊥ AB. Join OA, OB and OC 2s.png (i) By Pythagoras t...

5 years ago
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Answer to: Prove that the sum of the squares of the sides of rhombus is equal to the sum of the squares of its diagonals.

Given, ABCD is a rhombus whose diagonals AC and BD intersect at O. 2s.png Prove that, AB2 + BC2 + CD2 + AD2 = AC2 + BD2 Since, the diagonal...

5 years ago
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Answer to: ABC is an equilateral triangle of side 2a. Find each of its altitudes.

Given, ABC is an equilateral triangle of side 2a. 2s.png Draw, AD ⊥ BC In ΔADB and ΔADC, AB = AC AD = AD ∠ADB = ∠ADC [Both are 90°] T...

5 years ago
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Answer to: ABC is an isosceles triangle with AC = BC. If AB^2 = 2AC^2, prove that ABC is a right triangle.

Given, ΔABC is an isosceles triangle having AC = BC and AB2 = 2AC2 2s.png In ΔACB, AC = BC AB2 = 2AC2 AB2 = AC2 + AC2 = AC2 + BC2 [Sinc...

5 years ago
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Answer to: ABC is an isosceles triangle right angled at C. Prove that AB^2 = 2AC^2.

Given, ΔABC is an isosceles triangle right angled at C. 2s.png In ΔACB, ∠C = 90° AC = BC (By isosceles triangle property) AB2 = AC2 + BC2 [...

5 years ago
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Answer to: In Figure, ABD is a triangle right angled at A and AC ⊥ BD. Show that

(i) In ΔADB and ΔCAB, ∠DAB = ∠ACB (Each 90°) ∠ABD = ∠CBA (Common angles) ∴ ΔADB ~ ΔCAB [AA similarity criterion] ⇒ AB/CB = BD/AB ⇒ AB2 = CB ...

5 years ago
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Answer to: PQR is a triangle right angled at P and M is a point on QR such that PM ⊥ QR. Show that PM2 = QM × MR.

Given, ΔPQR is right angled at P is a point on QR such that PM ⊥QR 2s.png We have to prove, PM2 = QM × MR In ΔPQM, by Pythagoras theorem PQ...

5 years ago
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Answer to: Sides of triangles are given below. Determine which of them are right triangles? In case of a right triangle, write the length of its hypotenuse.

(i) Given, sides of the triangle are 7 cm, 24 cm, and 25 cm. Squaring the lengths of the sides of the, we will get 49, 576, and 625. 49 + 576 = 62...

5 years ago
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Answer to: Sides of two similar triangles are in the ratio 4 : 9. Areas of these triangles are in the ratio (A) 2 : 3 (B) 4 : 9 (C) 81 : 16 (D) 16 : 81

Sides of two similar triangles are in the ratio 4 : 9. 2s.png Let ABC and DEF are two similar triangles, such that, ΔABC ~ ΔDEF AB/DE = AC/...

5 years ago
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Answer to: ABC and BDE are two equilateral triangles such that D is the mid-point of BC. Ratio of the area of triangles ABC and BDE is

Given, ΔABC and ΔBDE are two equilateral triangle. D is the midpoint of BC. 2s.png ∴ BD = DC = 1/2BC Let each side of triangle is 2a. As, Δ...

5 years ago
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Answer to: Prove that the area of an equilateral triangle described on one side of a square is equal to half the area of the equilateral triangle described on one of its diagonals.

2s.png Given, ABCD is a square whose one diagonal is AC. ΔAPC and ΔBQC are two equilateral triangles described on the diagonals AC and side BC of ...

5 years ago
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Answer to: Prove that the ratio of the areas of two similar triangles is equal to the square of the ratio of their corresponding medians.

AM and DN are the medians of triangles ABC and DEF respectively and ΔABC ~ ΔDEF. 2s.png Area(ΔABC)/Area(ΔDEF) = AM2/DN2 Since, ΔABC ~ ΔDEF (G...

5 years ago
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Answer to: D, E and F are respectively the mid-points of sides AB, BC and CA of ΔABC. Find the ratio of the area of ΔDEF and ΔABC.

Given, D, E and F are respectively the mid-points of sides AB, BC and CA of ΔABC. 2s.png In ΔABC, F is the mid-point of AB (Already given) ...

5 years ago
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Answer to: If the areas of two similar triangles are equal, prove that they are congruent.

Given, ΔABC and ΔPQR are two similar triangles and equal in area 2s.png Now let us prove ΔABC ≅ ΔPQR. Since, ΔABC ~ ΔPQR ∴ Area of (ΔABC)/A...

5 years ago
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Answer to: In the figure, ABC and DBC are two triangles on the same base BC. If AD intersects BC at O, show that area (ΔABC)/area (ΔDBC) = AO/DO.

We know that ABC and DBC are two triangles on the same base BC. AD intersects BC at O. Area (ΔABC)/Area (ΔDBC) = AO/DO Let us draw two perpen...

5 years ago
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Answer to: Diagonals of a trapezium ABCD with AB || DC intersect each other at the point O. If AB = 2CD, find the ratio of the areas of triangles AOB and COD.

Given, ABCD is a trapezium with AB || DC. Diagonals AC and BD intersect each other at point O. 2s.png In ΔAOB and ΔCOD, we have ∠1 = ∠2 (Alte...

5 years ago
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Answer to: Let ΔABC ~ ΔDEF and their areas be, respectively, 64 cm^2 and 121 cm^2. If EF = 15.4 cm, find BC.

Given, ΔABC ~ ΔDEF, Area of ΔABC = 64 cm2 Area of ΔDEF = 121 cm2 EF = 15.4 cm As we know, if two triangles are similar, ratio of their area...

5 years ago
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Answer to: If AD and PM are medians of triangles ABC and PQR, respectively where ΔABC ~ ΔPQR prove that AB/PQ = AD/PM.

Given, ΔABC ~ ΔPQR 2s.png We know that the corresponding sides of similar triangles are in proportion. ∴ AB/PQ = AC/PR = BC/QR ……………(i) Als...

5 years ago
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Answer to: A vertical pole of a length 6 m casts a shadow 4m long on the ground and at the same time a tower casts a shadow 28 m long. Find the height of the tower.

Given, Length of the vertical pole = 6m Shadow of the pole = 4 m Let Height of tower = h m Length of shadow of the tower = 28 m In ΔABC and ΔD...

5 years ago
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Answer to: Sides AB and AC and median AD of a triangle ABC are respectively proportional to sides PQ and PR and median PM of another triangle PQR. Show that ΔABC ~ ΔPQR.

Two triangles ΔABC and ΔPQR in which AD and PM are medians such that; AB/PQ = AC/PR = AD/PM We have to prove, ΔABC ~ ΔPQR Let us construct first...

5 years ago
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