Question

plz solve solve it questions no.10,11,12,13

Answer 1

10 question is in the photo.
11.ABCD is a square and ABRS is a rhombus
AD=AS
∆ASD is isosceles triangle
angleASD+angleSAD+angleSDA=180°
2angleASD=180°-120°
angleASD=60°/2
angleASD=30°
now,angleSAB=angleSAD-angleDAB
=120°-90°=30°
angleSAB=30°
angleSAB=angleSRB(opposite angles of rhombus)
angleSRB=30°
12. ABCD is a kite
AC and BD intersect at 90°
In ∆BOC,
angleOBC+angleBOC+angleBCO=180°
65°+90°+angleBCO=180°
155°+angleBCO=180°
angleBCO=180°-155°
angleBCO=25°
angleACD=angleDAC=70°
angleBCD=angleBCO+angleACD
angleBCD=25°+70°
angleBCD=95°
angleADC=180°-70°-70°
angleADC180°-140°
angleADC=40°

13. ABCD is rhombus
AC=16cm
BD=12cm
side of rhombus =
$\sqrt{( \frac{d1}{2} )} {}^{2} + \sqrt{ (\frac{d2}{2} )} { }^{2} \\ \sqrt{ \frac{16}{2} } + \sqrt{ \frac{12}{2} } \\ \sqrt{ {8}^{2} } + \sqrt{6 {}^{2} } \\ \sqrt{64} + \sqrt{36} = \sqrt{100} \\ \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: = 10cm \\ lenghth \: of \: each \: side \: of \: a \: rhombus = 10cm$