Everything Maths Grade 10

21.The figure below shows a large triangle with verticesA,BandD, and a smaller triangle with vertices at
C,DandE. PointCis the mid-point ofBDand pointEis the mid-point ofAD.

B

55 ◦

D

A

39 ◦

E

?

C

a)The anglesA^= 39◦andB^= 55◦are given; determine the value ofDEC^.

b)The two triangles in this question are similar triangles. Complete the following statement correctly

by giving the three vertices in the correct order (there is only one correct answer).

△DECjjj △?

22.The figure below shows a large triangle with verticesM,NandQ, and a smaller triangle with vertices
atP,QandR. PointPis the mid-point ofN Qand pointRis the mid-point ofM Q.
N M
?

Q

22 ◦

P R

98 ◦

a)With the two angles given,Q^= 22◦andQRP^ = 98◦, determine the value ofM^.

b)The two triangles in this question are similar triangles. Complete the following statement correctly

by giving the three vertices in the correct order (there is only one correct answer).

△QM N jjj △?

23.Consider the triangle in the diagram below. There is a line segment crossing through a large triangle.
Notice that some segments in the figure are marked as equal to each other. One side of the triangle has
a given length of 10. Determine the value ofx.

12

9

10

x

24.In the figure below,GH ∥LJ, as labelled. Furthermore, the following lengths and angles are given:
GH= 10;LJ= 5;HJ= 9;KL= 8andG^= 84◦. The figure is drawn to scale.

278 7.5. Chapter summary