Questions & Solutions

1. Two angles of a triangle are 65° and 45°. Find the third angle.

Solution:

180^∘ − (65^∘+45^∘) = 70^∘

 Ans: 70°

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2. Find the area of a triangle with base = 14 cm and height = 10 cm.

Solution:

Area = 12×14×10 = 70 cm²

Ans: 70 cm²

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3. An equilateral triangle has a side of 7 cm. Find its perimeter.

Solution:

Perimeter = 3×7 = 21 cm

Ans: 21 cm

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4. A right-angled triangle has perpendicular = 6 cm and base = 4 cm. Find the hypotenuse.

Solution:

Hypotenuse = √6² + 4² = √36 + 16 = √52 = 2√13

Ans: 2√13 cm ≈ 7.21 cm

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5. The perimeter of a triangle is 36 cm. Two sides are 10 cm and 12 cm. Find the third side.

Solution:

Third side = 36 − (10 + 12) =14 cm

Ans: 14 cm

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