Ada yang bisa nomer 1,2&3 ? Tolong dong pake cara butuh banget

Ada yang bisa nomer 1,2&3 ? Tolong dong pake cara butuh banget

Nomor 1:
$frac{PR}{RT} = frac{PQ}{ST}$
$frac{PR}{21} = frac{7,5}{18}$
PR = $frac{21 . 7,5}{18}$
PR = 8,75 cm

Nomor 2:
$frac{CE}{CB} = frac{DE}{AB}$
$frac{CE}{CE + BE} = frac{30}{36}$
36 CE = 30 × (CE + 4)
36 CE = 30 CE + 120
36 CE – 30 CE = 120
6 CE = 120
CE = 20 cm

Nomor 3:
$frac{XY}{24} = frac{WZ}{40}$
$frac{XY}{24} = frac{15}{40}$
XY = $frac{24 . 15}{40}$
XY = 9 cm

$frac{WX}{32} = frac{WZ}{40}$
$frac{WX}{32} = frac{15}{40}$
WX = $frac{32 . 15}{40}$
WX = 12 cm
YZ = 12 cm

Keliling = WX + XY + YZ + WZ
Keliling = 12 + 9 + 12 + 15
Keliling = 48 cm