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Standard VIII

Mathematics

Area of a General Quadrilateral

In triangle A...

Question

In triangle ABC if A=7cm, B=5cm and C=8cm, Find the area of triangle ABC

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Solution

$\begin{matrix} A = 7 c m, B = 5 c m, C = 8 c m S = \frac{A + B + C}{2} = \frac{7 + 5 + 8}{2} = 10 a r e a = \sqrt{s (s - a) (s - b) (s - c)} = \sqrt{10 (10 - 7) (10 - 5) (10 - 8)} = 10 \sqrt{3} = 17.31 c m^{2} . \end{matrix}$

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Similar questions

Q. In

△ A B C, ∠ A B C = ∠ D A C, A B = 8 c m, A C = 4 c m, A D = 5 c m

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Q. Triangles

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Q. Triangles ABC and DEF are similar.

(i) If area (∆ABC) = 16 cm², area (∆DEF) = 25 cm² and BC = 2.3 cm, find EF.
(ii) If area (∆ABC) = 9 cm², area (∆DEF) = 64 cm² and DE = 5.1 cm , find AB.
(iii) If AC = 19 cm and DF = 8 cm, find the ratio of the area of two triangles.
(iv) If area (∆ABC) = 36 cm², area (∆DEF) = 64 cm² and DE = 6.2 cm, find AB.
(v) If AB = 1.2 cm and DE = 1.4 cm, find the ratio of the areas of ∆ABC and ∆DEF.

AE is a median to side BC of triangle ABC. If area(∆ABC) = 24 cm, then area(∆ABE) =

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In triangle ABC if A=7cm, B=5cm and C=8cm, Find the area of triangle ABC

A=7cm,B=5cm,C=8cmS=A+B+C2=7+5+82=10area=√s(s−a)(s−b)(s−c)=√10(10−7)(10−5)(10−8)=10√3=17.31cm2.

$\begin{matrix} A = 7 c m, B = 5 c m, C = 8 c m S = \frac{A + B + C}{2} = \frac{7 + 5 + 8}{2} = 10 a r e a = \sqrt{s (s - a) (s - b) (s - c)} = \sqrt{10 (10 - 7) (10 - 5) (10 - 8)} = 10 \sqrt{3} = 17.31 c m^{2} . \end{matrix}$