Area of \(\triangle ABC=\frac{1}{2}\times Base \times Height\)
\(=\frac{1}{2}\times BC\times AD\)
\(\frac{1}{2}\times 9\times 6=27\;cm^2\)
Area of \(\triangle ABC = \frac{1}{2}\times AB\times CE\)
\(27=\frac{1}{2}\times7.5\times CE\)
\(CE =7.2\;cm\)
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. |