DOES ANYONE KNOW HOW TO DO THIS WILL MARK BRAINLIEST

IM WORKING WITH "Find the area of the following ellipse."

#1 Find the area of the following ellipse. (Round answer to the nearest tenth. Express answer in cm²)
REMEMBER: To convert from in² to cm², just multiply by 2.54².

a = 4 in.; b = 7 in.

A =cm²

#2 Find the area of the following ellipse. (Round answer to the nearest tenth).

2a = 10 cm; 2b = 20 cm.

A =cm²

#3 Find the area of the following ellipse. (Round answer to the nearest hundredth).

a = 4.5 m; b = 5.5 m

Area (to the nearest hundredth) = m²

#4 Find the area of the following ellipse. (Round answer to the nearest tenth).

a = 3 ft.; b = 4.5 ft.

Area (to the nearest tenth) = sq. ft.