Question

What is triangle ???? Give smae question of its area with solutions

Answer 1

Answer:

a plane figure with three straight sides and three angles is called triangle.

Step-by-step explanation:

Solved Examples⤵️

➪ If ABC is a triangle where AB = 3cm, BC=5cm and AC = 4cm, then find its perimeter.

Solution: Given, ABC is a triangle.

AB = 3cm

BC = 5cm

AC = 4cm

As we know by the formula,

Perimeter = Sum of all three sides

P = AB + BC + AC

P = 3+5+4

P = 12cm

➪ Find the area of a triangle having sides 5,6 and 7 units length.

Solution- Using Heron’s formula to find the area of a triangle-

Semiperimeter (s) = (a+b+c)/2

s = (5 + 6 +7)/2

s = 9

Now Area of a triangle = √[s(s-a)(s-b)(s-c)]

=√[9(9-5)(9-6)(9-7)]

=√ [9 × 4 × 3 × 2]

=√ [3 × 3 × 2 × 2 × 3 × 2]

=√ [32 × 22 × 3 × 2]

= 6√6 square units.

➪Find the area of triangle PQR if p = 6.5 cm, r = 4.3 cm and Q = 39˚. Give your answer correct to 2 decimal places.

Area of triangle PQR

= 1/2 pr sin Q

= 1/2 × 6.5 × 4.3 × sin 39˚ = 8.79 cm²

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