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Mathematics Grade 9 Unit 7: CONGRUENCY AND SIMILARITY

national exam questions have come from this unit. It runs 39 pages; one careful study pass takes about 2.5 hours, and its difficulty is easier among Mathematics units. Each section below lists the questions set from it, with the year, and opens the page that teaches it.

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7.1 Revision on Congruency of Triangles _ _ · read p. 240
Not asked in a national paper yet.
7.2 Definition of Similar Figures · read p. 245
Not asked in a national paper yet.
7.3 Theorems on Similar Plane Figures _ _ _ · read p. 249
  • 2018 E.C., Q18 – There is a right-angle symbol at vertex B and another right- angle symbol where the line segment BD meets the hypotenuse AC at point D.]
  • 2017 E.C., Q16 – In the figure shown below, $\overline{AC} = \overline{DE}$, $\angle BAC = \angle DEF$, $\angle ACB = \angle FDE$ and $\overline{AC}\equiv \overline{DE}$ Then which one of the following is true?
7.4 Ratio of Perimeters of Similar Plane Figures · read p. 259
Not asked in a national paper yet.
7.5 Ratio of Areas of Similar Plane Figures_ · read p. 262
  • 2017 E.C., Q39 – Suppose two triangles are similar by SSS similarity theorem. If the side lengths of one triangle are 2 cm, 4 cm and 6 cm, and the shorter side of the other triangle is 9 cm long, then what are the lengths (in cm) of the
  • 2017 E.C., Q49 – A boy and girl are both standing on a sun light. The boy’s height is 1.6m and casts a shadow of 2m. If the girl’s height casts a shadow of 1.8m, then what is the height (in meter) of the girl?
  • 2017 E.C., Q43 – A person, whose height is 2 m, is standing away from a 16 m tall building. The angle of depression from the top of the building to the head of the person is $30^\circ$. How far is the person from the building in meters?
  • 2014 E.C., Q32 – If the perimeter of a rectangle is 120 m, what are the length l and width w of the rectangle that maximizes its area?
7.6 Construction of Similar Plane Figure_ _ _ · read p. 265
Not asked in a national paper yet.
7.7 Applications of Similarities · read p. 267
Not asked in a national paper yet.