NCERT Exemplar Solutions
Class 7 - Mathematics - Unit 9: Perimeter and Area - Multiple Choice QuestionsQuestion 16
Class 7 - Mathematics - Unit 9: Perimeter and Area - Multiple Choice Questions
Question. 16
16. In Fig. 9.21, if PR = 12 cm, QR = 6 cm and PL = 8 cm, then QM is
(a)
(a) 6 cm
(b)
(b) 9 cm
(c)
(c) 4 cm
(d)
(d) 2 cm
Detailed Answer with Explanation:
Using right triangle properties:
Area of ΔPLR = \( \tfrac{1}{2} PL \times QR = \tfrac{1}{2} \times 8 \times 6 = 24 \).
Also, area = \( \tfrac{1}{2} PR \times QM = \tfrac{1}{2} \times 12 \times QM \).
So, 24 = 6 × QM ⇒ QM = 4 cm.