NCERT Class 7 Mathematics

PRACTICAL GEOMETRY 199 EXERCISE 10.2 ConstructΔXYZ in which XY = 4.5 cm, YZ = 5 cm and ZX = 6 cm. Construct an equilateral tria ...

200 MATHEMATICS Step 5 Join PR. ΔPQR is now obtained(Fig 10.5(v)). Let us now construct another triangle ABC such that AB = 3 cm ...

PRACTICAL GEOMETRY 201 10.6 CONSTRUCTING A TRIANGLE WHEN THE MEASURES OF TWO OF ITS ANGLES AND THE LENGTH OF THE SIDE INCLUDED B ...

202 MATHEMATICS Now, draw another ΔLMN, where m∠NLM = 30°, LM = 6 cm and m∠NML = 100°. Take a cutout of ΔLMN and place it on the ...

PRACTICAL GEOMETRY 203 Step 3At M, draw MX ⊥ MN. (L should be somewhere on this perpendicular) [Fig 10.7(iii)]. Step 4 With N as ...

204 MATHEMATICS Miscellaneous questions Below are given the measures of certain sides and angles of triangles. Identify those wh ...

11.1 INTRODUCTION In Class VI, you have already learnt perimeters of plane figures and areas of squares and rectangles. Perimete ...

206 MATHEMATICS Perimeter of a rectangle = 2 × (l + b) Area of a rectangle =l × b, Area of a square = side × side Tanya needed a ...

PERIMETER AND AREA 207 Area of the rectangle =l × b (where b = width of the sheet) Therefore, width b = Area l 500 25 = 20 cm Pe ...

208 MATHEMATICS It is given that, The area of the rectangle = The area of the square Area of the rectangle = 1600 cm^2 , breadth ...

PERIMETER AND AREA 209 11.2.1 Triangles as Parts of Rectangles Take a rectangle of sides 8 cm and 5 cm. Cut the rectangle along ...

210 MATHEMATICS Each of the following rectangles of length 6 cm and breadth 4 cm is composed of congruent polygons. Find the are ...

PERIMETER AND AREA 211 Any side of a parallelogram can be chosen as baseof the parallelogram. The perpendicular dropped on that ...

212 MATHEMATICS consider the following parallelograms with sides 7 cm and 5 cm (Fig 11.13). Fig 11.13 Find the perimeter and are ...

PERIMETER AND AREA 213 Draw a scalene triangle on a piece of paper. Cut out the triangle. Place this triangle on another piece o ...

214 MATHEMATICS Consider the obtuse-angled triangle ABC of base 6 cm (Fig 11.16). Its height AD which is perpendicular from the ...

PERIMETER AND AREA 215 EXAMPLE 9 Find the area of the following triangles (Fig 11.20). (i) Fig 11.20 (ii) SOLUTION (i) Area of t ...

216 MATHEMATICS (ii) PR = base = 8 cm QM = height =? Area = 10 cm^2 Area of triangle = 1 2 ××bh i.e., 10 =^1 2 ×× 8 h h= 10 4 = ...

PERIMETER AND AREA 217 Find the missing values: PQRS is a parallelogram (Fig 11.23). QM is the height from Q to SR and QN is th ...

218 MATHEMATICS to decorate these cards. What length of the lace does she require for each? (Fig 11.28) (a) (b) (c) Fig 11.28 Yo ...