A square-based pyramid has a base edge length of 4 cm and a height of 3 cm. What is its surface area?

4. Which of the following can be the sides of a right triangle? (i) \( 2.5 \mathrm{~cm}, 6.5 \mathrm{~cm}, 6 \mathrm{~cm} \). (iii) \( 2 \mathrm{~cm}, 2 \mathrm{~cm}, 5 \mathrm{~cm} \). (iii) \( 1.5 \mathrm{~cm}, 2 \mathrm{~cm}, 2.5 \mathrm{~cm} \).

3 треугольнике \( A B C \) к стороне \( A B=9 \) см опущена высота, длина которой составила 8 см Найди площадь этого треугольника и дай ответ з квадратных сантиметрах.

\( =11 \mathrm{~cm}^{2} \) Example 2 The area of a sector of a circle is 38.5 cm if the angle subtended at the centre is 90

5. A tree is broken at a height of 5 m from the ground and its top touches the ground at a distance of 12 m from the base of the tree. Find the original height of the tree.

A tree is broken at a height of 5 m from the ground and its top touches the ground at a distance of 12 m from the base of the tree. Find the original height of the tree.