+0

# Geometry

0
268
3
+51

My teacher hasn't taught the topic yet, but thinks we can do this without any guidance. Can you please help.

May 6, 2018

#1
+2

Both questions begin by making use of the Pythagoras theorem.

For the first one, start by saying that 9^2 + r^2 = (6 + r)^2, tidy up and solve for r.

The second one is asking you if the triangle is rightangled (Pythagoras again), if it is then ST will be a tangent.

May 6, 2018
#2
+2

Q1:

(6+r)2 = 92 + r2

62 + 2*6*r+r2 =  92 + r2

62 + 2*6*r =  92

2*6*r =  92 - 62

r = ( 92 - 6) / ( 2*6 )

Q2:

by using pythagoras rule

if    RT2 = RS+ ST2    is true , ST is tangent to the circle.

(5+8)2   =    5+ 122

(13)2   =    5+ 122

169    =    25 + 144

169    =    169

yas

May 6, 2018
edited by Guest  May 6, 2018
#3
+51
+1

Thank you very much for your help, you really helped me understand how to do these probelms. You're wonderful!

melvsky  May 6, 2018
{"found_math": false, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 0, "mathjax_display_tex": 0, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0}