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If the length of an arc of the sector of a circle is 20 cm and if the radius is 7 cm, find the area of the sector.
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If sinθ = `8/17`, where θ is an acute angle, find the value of cos θ by using identities.
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`sqrt((1-cos"A")/(1+cos"A"))=cos"ecA - cotA"`
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In ΔPQR, ∠P = 30°, ∠Q = 60°, ∠R = 90° and PQ = 12 cm, then find PR and QR.
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ΔAMT∼ΔAHE, construct Δ AMT such that MA = 6.3 cm, ∠MAT=120°, AT = 4.9 cm and `"MA"/"HA"=7/5`, then construct ΔAHE.
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In right angled triangle, if sum of the squares of the sides of right angle is 169, then what is the length of the hypotenuse?
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A rectangle having length of a side is 12 and length of diagonal is 20, then what is length of other side?
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If the length of diagonal of square is √2, then what is the length of each side?
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If length of both diagonals of rhombus are 60 and 80, then what is the length of side?
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In ∆ABC, AB = `6sqrt(3)` cm, AC = 12 cm, and BC = 6 cm, then m∠A = ?
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If a triangle having sides 50 cm, 14 cm and 48 cm, then state whether given triangle is right angled triangle or not
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If a triangle having sides 8 cm, 15 cm and 17 cm, then state whether given triangle is right angled triangle or not
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A rectangle having dimensions 35 m × 12 m, then what is the length of its diagonal?
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In ∆LMN, l = 5, m = 13, n = 12 then complete the activity to show that whether the given triangle is right angled triangle or not.
*(l, m, n are opposite sides of ∠L, ∠M, ∠N respectively)
Activity: In ∆LMN, l = 5, m = 13, n = `square`
∴ l2 = `square`, m2 = 169, n2 = 144.
∴ l2 + n2 = 25 + 144 = `square`
∴ `square` + l2 = m2
∴By Converse of Pythagoras theorem, ∆LMN is right angled triangle.
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In ΔABC, AB = 9 cm, BC = 40 cm, AC = 41 cm. State whether ΔABC is a right-angled triangle or not. Write reason.
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Prove that: (sec θ – cos θ) (cot θ + tan θ) = tan θ.sec θ
Proof: L.H.S. = (sec θ – cos θ) (cot θ + tan θ)
= `(1/square - cos θ) (square/square + square/square)` ......`[∵ sec θ = 1/square, cot θ = square/square and tan θ = square/square]`
= `((1 - square)/square) ((square + square)/(square square))`
= `square/square xx 1/(square square)` ......`[(∵ square + square = 1),(∴ square = 1 - square)]`
= `square/(square square)`
= tan θ.sec θ
= R.H.S.
∴ L.H.S. = R.H.S.
∴ (sec θ – cos θ) (cot θ + tan θ) = tan θ.sec θ
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In the given figure, triangle PQR is right-angled at Q. S is the mid-point of side QR. Prove that QR2 = 4(PS2 – PQ2).

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In a right angled triangle, right-angled at B, lengths of sides AB and AC are 5 cm and 13 cm, respectively. What will be the length of side BC?
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In the figure given above, `square`ABCD is a square and a circle is inscribed in it. All sides of a square touch the circle. If AB = 14 cm, find the area of shaded region.
Solution:
Area of square = `(square)^2` ......(Formula)
= 142
= `square "cm"^2`
Area of circle = `square` ......(Formula)
= `22/7 xx 7 xx 7`
= 154 cm2
(Area of shaded portion) = (Area of square) - (Area of circle)
= 196 − 154
= `square "cm"^2`
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In the given figure, altitudes YZ and XT of ∆WXY intersect at P. Prove that,
- `square`WZPT is cyclic.
- Points X, Z, T, Y are concyclic.

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