NCERT Exemplar Solutions
Class 7 - Mathematics - Unit 9: Perimeter and Area - Problems and SolutionsQuestion 122
Class 7 - Mathematics - Unit 9: Perimeter and Area - Problems and Solutions
Question. 122
In Fig. 9.65, triangle AEC is right-angled at E, B is a point on EC, BD is the altitude of triangle ABC, AC = 25 cm, BC = 7 cm and AE = 15 cm. Find the area of triangle ABC and the length of DB.
Answer:
Area of triangle ABC = 84 cm², DB = 24 cm.
Detailed Answer with Explanation:
Use Pythagoras to find EC = 20 cm. Then AB = 25 cm, base × height gives area. Altitude DB computed by formula \(BD = 2 \times \text{Area} / AC\).