\(Area \;of\; triangle = \frac{1}{2} \times Base \times Height\)
(a) \(Base = 4 \;cm, \;height= 3 \;cm\)
\(Area = \frac{1}{2}\times4\times3\)
= \(6\; cm^2\)
(b) \(Base = \;5 cm, \;height= 3.2 \;cm\)
\(Area = \frac{1}{2}\times5\times3.2\)
= \(8\; cm^2\)
(c) \(Base = 4 \;cm,\; height= 3\; cm\)
\(Area = \frac{1}{2}\times4\times3\)
= \(6\; cm^2\)
(d)\(Base = 3\; cm, \;height= 2\; cm\)
= \(\frac{1}{2}\times2\times3\)
= \(3\; cm^2\)
Base | Height | Area of triangle |
---|---|---|
15 cm | - | 87 \(cm^2\) |
- | 31.4 mm | 1256 \(mm^2\) |
22 cm | - | 170.5 \(cm^2\) |
Match the items given in Column I with one or more items of Column II.
Column I | Column II |
(a) A plane mirror | (i) Used as a magnifying glass. |
(b) A convex mirror | (ii) Can form image of objects spread over a large area. |
(c) A convex lens | (iii) Used by dentists to see enlarged image of teeth. |
(d) A concave mirror | (iv) The image is always inverted and magnified. |
(e) A concave lens | (v) The image is erect and of the same size as the object. |
- | (vi) The image is erect and smaller in size than the object. |