Kupeza kozungulira kwa trapezoid: chilinganizo ndi ntchito

M'bukuli, tiwona momwe tingawerengere kuzungulira kwa trapezoid ndikusanthula zitsanzo zothetsera mavuto.

Fomula ya Perimeter

Mzere (P) wa trapezoid ndi wofanana ndi kuchuluka kwa utali wa mbali zake zonse.

P = a + b + c + d

• b и d - maziko a trapezoid;
• a и с - mbali zake.

Kuzungulira kwa isosceles trapezoid

Mu isosceles trapezoid, mbali zake ndi zofanana (uXNUMXd c), ndichifukwa chake amatchedwanso isosceles. Perimeter imawerengedwa motere:

P = 2a + b + d or P = 2s + b + d

Kuzungulira kwa trapezoid yamakona anayi

Kuti muwerenge mozungulira, njira yomweyo imagwiritsidwa ntchito ngati scalene trapezoid.

P = a + b + c + d

Zitsanzo za ntchito

Ntchito 1

Pezani zozungulira za trapezoid ngati maziko ake ndi 7 cm ndi 10 cm ndipo mbali zake ndi 4 cm ndi 5 cm.

Kusankha:

Timagwiritsa ntchito ndondomeko yokhazikika, m'malo mwake kutalika kwa mbali zodziwika: P u7d 10 cm + 4 cm + 5 cm + 26 cm uXNUMXd XNUMX cm.

Ntchito 2

Kuzungulira kwa isosceles trapezoid ndi 22 cm. Pezani kutalika kwa mbali ngati maziko a chithunzicho ndi 3 cm ndi 9 cm.

Kusankha:

Monga tikudziwira, perimeter ya isosceles trapezoid imawerengedwa ndi chilinganizo: P = 2a + b + dKodi а – mbali.

Kutalika kwake kuchulukitsidwa ndi ziwiri ndi: 2a = P - b - d = 22 cm - 3 cm - 9 cm = 10 cm.

Choncho, kutalika kwa mbali ndi: a = 10 cm / 2 = 5 cm.